Jamere Jackson
Chief Financial Officer, Executive Vice President - Finance and Store Development, Customer Satisfac at AutoZone
Thanks, Bill, and good morning, everyone. As Bill mentioned, we had another great quarter. Our growth initiatives are continuing to deliver strong results and the efforts of our AutoZoners in our stores and distribution centers have enabled us to maintain strong results.
To start this morning, let me take a few minutes to elaborate on the specifics in our P&L for Q4. For the quarter, total auto parts sales, which includes our Domestic, Mexico and Brazil stores were $4.8 [Phonetic] billion, up 8%. And for the total year, our total auto parts sales were $14.4 billion, up 15.9%.
Now let me give a little more color on sales and our growth initiatives. Starting with our commercial business, for the fourth quarter our domestic DIFM sales increased 21% to $1.2 billion and were up 31% on a two year stack basis. Sales to our DIFM customers represented 24% of our total sales and our weekly sales per program were $14,400, up 18% as we averaged $74 million in total weekly commercial sales. Once again, our growth was broad-based as national and local accounts all grew over 20% in the quarter.
For the full-year, our commercial sales grew 22.6% and 29% on a two-year stack basis. Our execution of our commercial acceleration initiatives is delivering exceptional results as we focus on building a faster growing business. The disciplined investments we're making are helping us grow share and we're making tremendous progress and growing our business in this highly fragmented portion of the market.
We now have our commercial program in over 86% of our domestic stores and we're focused on building our business with national, regional and local accounts. This quarter, we opened 72 net new programs, finishing with 5,179 total programs. We continue to leverage our DIY infrastructure and increased our share of wallet with existing customers. In fiscal year '22, commercial growth will lead the way.
Our growth strategies continue to work as we continue to grow share. We are confident in our strategies and execution, and believe we will continue to gain share. We remain focused on delivering improvements in the quality of our parts, particularly with our Duralast brand, making improvements in our assortment, maintaining competitive pricing and staying committed to providing exceptional service. These core focus areas have enabled us to drive double-digit sales growth for the past five quarters and positioned us well in the marketplace.
As we move forward, we're focused on our core initiatives that we believe will accelerate our sales even further. Let me highlight one key initiatives that is driving our performance and positioning us for an even brighter future in our commercial and retail businesses, and that's our mega hub strategy. Our mega hub strategy is giving us tremendous momentum and we are doubling down. We now have 58 mega hub locations and we expect to open approximately 20 more over the next 12 months. As a reminder, our mega hubs typically carry roughly 100,000 SKUs and drive tremendous sales lift inside the store box, as well as serve as the fulfillment source for other stores.
The expansion of coverage and parts availability continues to deliver a meaningful sales lift to both our commercial and DIY business, and we're testing greater density of mega hubs to drive even better sales results. With this effort, we are leveraging sophisticated analytics to help us expand our market reach, give us closer proximity to our customers and improve our product availability and delivery times.
I will remind you that our current mega hub strategy envisions our expansion to a total of 100 to 110 mega hubs. However, as these assets continue to outperform our expectations, we would expect to expand significantly further. We are excited about this work and its ability to further accelerate our commercial growth. All of our efforts are building meaningful competitive advantage and give us tremendous confidence in our ability to create a faster growing business.
On the retail side of our business, our domestic retail business was down just 40 basis points, but up 23.4% on a two year stack. For the full-year, the retail business was up 11.2% and 18.7% on a two year stack basis. The business has been remarkably resilient as we have gained and maintained nearly 300 points of market share since the start of the pandemic. We are excited about the initiatives that drove the tremendous sales and share growth and the relentless focus on execution by our AutoZoners in our stores and distribution centers has been remarkable. We are winning in the marketplace and the execution of our AutoZoners, who are taking care of our customers remains a key competitive advantage.
As we exit fiscal '21, I'm really pleased with the competitive positioning of our DIY business and our outlook going forward. The work we have done on improving the customer shopping experience, expanding assortment, leveraging our hub and mega hub network and maintaining competitive pricing have led to tremendous results over the last two years. DIY has been a strong contributor to the growth of our company and while comps are difficult, because of our strong past performance, the fundamentals of our business have never been stronger. Our strategy and execution are delivering solid results.
Now, I'll say a few words regarding our international business. We continue to be pleased with the progress we're making in Mexico and Brazil. During the quarter, we opened 29 new stores in Mexico to finish with 664 stores and five new stores in Brazil to finish with 52. On a constant currency basis, we saw accelerated sales growth in both countries. Most importantly, as those economies stabilize, we remain committed to our store opening schedules in both markets and expect both to be significant contributors to sales and earnings growth in the future.
Now let me spend a few minutes on the P&L and gross margins. For the quarter, our gross margin was down 82 basis points, driven primarily by the accelerated growth in our commercial business, where the shift in mix coupled with the investment in our initiatives drove margin pressure, but increased our gross profit dollars by 6.4%. I mentioned on last quarter's call that we expected to have our gross margin down in a similar range to our third quarter, where we were down 118 basis points.
However, the team has been focused on driving margin improvements, primarily through pricing actions that offset inflation to drive a better-than-expected outcome. As Bill mentioned earlier in the call, we're beginning to see cost inflation in certain product categories along with rising transportation costs. To be clear, overall we have pricing power and consistent with prior inflationary cycles, we have been successful thus far at passing these higher cross through our retails.
Overall, the industry pricing remains rational and we're pricing accordingly. All of the actions we are taking have resulting [Phonetic] in us growing our DIY and DIFM businesses at a significantly faster rate than the overall market and we're committed to capturing our fair share, while improving our competitive positioning in a disciplined way. We should expect our margins in the first quarter to be down in a similar range to the fourth quarter. We are however focused on driving new customers to AutoZone and over time growing absolute gross profit dollars at a faster than historic rate in our total auto parts operating segment.
Moving to operating expenses. Our expenses were, up 9.2% versus last year's Q4 as SG&A as a percentage of sales deleveraged 33 basis points. The deleverage was primarily driven by higher payroll expenses to support our sales and customer service initiatives and higher IT investments that underpin our growth initiatives. These dynamics were partially offset by lower pandemic-related expenses in the previous year.
While our SG&A dollar growth rate has been higher than historical averages, we've been focused on maintaining high levels of customer service during a period of accelerated growth and taking care of our AutoZoners' during these difficult times. We will continue to be disciplined on SG&A growth as we move forward and manage expenses in line with sales growth over time.
Moving to the rest of the P&L, EBIT for the quarter was just over $1 billion, up 2.6% versus prior year's quarter, driven by strong topline growth. EBIT for fiscal year '21 was just over $2.9 billion, up 21.8% versus fiscal year '20. Interest expense for the quarter was just over $58 million, down 11.5% from Q4 a year ago as our debt outstanding at the end of the quarter was just under $5.3 billion versus just over $5.5 billion last year. We're planning interest in the $46 million to $48 million range for the first quarter of fiscal 2022 versus $46 million in last year's first quarter.
For the quarter, our tax rate was 20.3% versus 22.3% in last year's fourth quarter. This quarter's rate benefited 215 basis points from stock options exercised, while last year it benefited 35 basis points. For the first quarter of 2022, we suggest investors model us at approximately 23.6% before any exemptions on credits due to stock option exercises.
Moving to net income and EPS. Net income for the quarter was $786 million, up 6.1% versus last year's fourth quarter. Our diluted share count of 22 million was lower by 8.1% from last year's fourth quarter. The combination of higher earnings and lower share count drove earnings per share for the quarter to $35.72, up 15.5% over the prior year's fourth quarter. Net income per share for fiscal year '21 was $95.19, up a remarkable 32.3%, reflecting our outstanding topline performance and lower share count.
Now let me talk about our cash flow. For the fourth quarter, we generated $1.3 billion of operating cash. Our operating cash flow results continue to benefit from strong sales and earnings previously discussed. You should expect us to be an incredibly strong cash flow generator going forward, and we remain committed to returning meaningful amounts of cash to our shareholders.
Regarding our balance sheet, we now have nearly $1.2 billion in cash on the balance sheet and our liquidity position remains strong. We are also managing our inventory well, as our inventory per store growth was up four-tenths of a percent versus Q4 last year. Total inventory increased 3.7% over the same period last year, driven by new stores.
Net inventory defined as merchandise inventories less accounts payable on a per store basis was a negative $203,000 versus negative $104,000 last year and negative $167,000 last quarter. As a result, accounts payable as a percent of gross inventory finished the quarter at 129.6% versus last year's Q4 of 115.3%.
Lastly, I'll spend a moment on capital allocation and our share repurchase program. We repurchased $900 million of AutoZone stock in the quarter. As of the end of the fiscal quarter, we had approximately 21.1 million shares outstanding. At quarter end, we had just over $418 million remaining under our share buyback authorization and over $900 million of excess cash.
For the full-year, we bought back $3.4 billion of stock or approximately 2.6 million shares. The powerful free cash flow we have generated this year combined with excess cash carried over from last year has enabled us to buyback over 11% of our shares outstanding at the beginning of the year. We have bought back nearly 90% of the shares outstanding of our stock since our buyback inception in 1998, while investing in our existing assets and growing our business. We remain committed to this disciplined capital allocation approach where we expect to have powerful free cash flows that will enable us to invest in the business and return meaningful amounts of cash to shareholders.
So, to wrap up, we had another very strong quarter highlighted by strong comp sales, which drove a 6.1% increase in net income and a 15.5% increase in EPS. We are driving long-term shareholder value by investing in our growth initiatives driving robust earnings and cash and returning excess cash to our shareholders. Our strategy is working and I have tremendous confidence in our ability to drive significant and ongoing value for our shareholder.
Now, I will turn it back to Bill.