Vice President, Interim Chief Financial Officer and Treasurer at Rollins
Thank you, Jerry. As we measure our performance and think about how to best articulate Rollins' business in the future along with what routine questions we've received from the investment community, we will now be presenting three additional measurements quarterly moving forward. The first is a measure we have referred to periodically and that is EBITDA or earnings before interest, taxes, depreciation and amortization. Due to our consistent high volume of acquisitions and hence high amortization expense related to these acquisitions, presenting EBITDA regularly will provide a clear picture of our operations ongoing financial performance. Think about this, over the last three years we have averaged 30 acquisitions per year. Next we will begin presenting our revenue growth through both constant exchange rate and actual exchange rate. By utilizing historical baseline revenues for acquisitions [Indecipherable] through the due diligence process, we were able to include all acquisitions within the calculations, both standalone and tuck-in. This will bring clarity and consistency to both our acquisition and our organic revenue growth measurements. Third, we will be providing you with our free cash flow. We believe that this will properly illustrate Rollins' strong ability to generate cash. We have taken a simple approach to defining free cash flow, which is calculated as net cash provided by operating activities less purchase of equipment and property. Our hope is that these measurements will enable investors to better assess our operating performance in the future and provide a deeper view of our business. We have included GAAP to non-GAAP reconciliations on each of these metrics on our earnings press release published this morning.
So onto the numbers. Our third quarter revenues of $650.2 million was an increase of 11.4% over last year. Of the 11.4% actual exchange rate revenue growth, acquisition growth was 2.2%, and organic equated to 9.2%. For the constant exchange rate, the growth percentage is calculated within the hundreds of the actual exchange growth rate therefore presented the same. For the nine months ended September 2021, revenue of $1.824 billion was an increase of 12.12 percentage over year-to-date 2020. Of this actual exchange rate total revenue growth of 2. -- or excuse me, of 12.2%, 2.7% was related to acquisitions, and 9.5% organic growth. The constant year-to-date exchange rate total revenue growth for 2021 equaled 11.6%; 2.7% represented acquisitions and 8.9% organic revenue growth.
As Jerry pointed out, residential, commercial and termite all grew double-digits this quarter over the same quarter last year. So, in determining my focus for today, I decided to take Jerry's lead and discuss wildlife, yet I'm discussing specifically company owned wildlife operations. For the third quarter in 2021, wildlife revenues grew 24.1% over last year, and year-to-date wildlife has presented an overall revenue growth of 27.6%. What makes us particularly impressive at this is that this is after their strong growth of 20.4% last year. So similar to our residential pest control, wildlife did not feel a negative impact to revenue growth during the pandemic. The way to go to the wildlife team. Now onto our income. For the third quarter and year-to-date, we are presenting adjusted EBITDA for comparison purposes due to the one-time super vesting of our late Chairman stock grants in the third quarter of 2020 and the impact of our gain on sale of several of our core properties in the first six months of 2021. So, third quarter 2021 EBITDA was $150.9 million or 8.7% over 2020 third quarter adjusted EBITDA of $138.9 million. Third quarter 2021 EPS was $0.19 per diluted share or 5.6% improvement over the 2020 third quarter adjusted EPS. For the nine months ended September 2021, our adjusted EBITDA was $422 million or 22.1% over last year's adjusted EBITDA of $344.9 million. Year-to-date 2021 adjusted EPS was $0.53 per diluted share or 26.2% over last year. For the third quarter 2021, gross margin increased to 53% or 0.4% over last year. Strong improvements in our materials and supplies were negatively offset by high overall fleet costs primarily from an increase in fuel of approximately $4 million over third quarter 2020, and lower vehicle gains of $900,000 compared to last year.
Sales, general and administrative third quarter margin increase over last year was strongly impacted by the PPE donations and the SEC accrual previously mentioned by John. Travel expenses have also increased $1.3 million in the third quarter as we have begun to lift our company travel restrictions. Amortization expenses for the third quarter 2021 increased $1.4 million due to the amortization of customer contracts from multiple acquisitions. This was offset by a decrease in depreciation of $201,000 due to the sale of owned vehicles and centralizing of IT function. Overall, this equated to a 5.1% increase in depreciation and amortization over the third quarter 2020. Our dividends paid year-to-date 2021 was $119.7 million or an increase of 30.4% over last year. We ended the current period with $117.7 million in cash, of which $73.6 million was held by our foreign subsidiaries.
So, this brings us to the final of our new three measurements, free cash flow. For the third quarter of 2021, our free cash flow is $72.9 million or a decrease of 27.5% over the same quarter last year. For the nine months ended 2021, our free cash flow equal $278.9 million or 13.6% decrease over year-to-date 2020. This fluctuation occurred due to the deferral of $30.3 million in FICA taxes payable in 2020 as allowed under the CARES Act. These associated taxes were then remitted in September of 2021. We hope that with he discussion of these new measurements you will receive a greater clarity while reviewing our financial performance.
Lastly, I want to discuss that yesterday we were extremely pleased to announce that our Board has approved a 25% increase to our dividends. The quarterly dividend increased to $0.10 per share from $0.08 per share and will be paid on December 10, 2021 to stockholders of record at the close of business on November 10, 2021. Additionally, the Board also approved a special dividend of $0.08 to be paid on December 10, 2021 as well. The dividend increase reflects our strong performance in the first nine months of the year and underscores our financial strength, our solid capital position, and the Board's confidence in our outlook for continued growth.
John, I'll turn it back to you.