Christopher J. Nassetta
President and Chief Executive Officer at Hilton Worldwide
Thank you, Jill. Good morning, everyone, and thanks for joining us today. As our results show, we made significant progress in our recovery throughout 2021. We saw a meaningful increase in demand for travel and tourism and our team members around the world were there to welcome guests with our signature hospitality as they look to reconnect and create new memories. We continued to demonstrate our resiliency by remaining laser-focused on providing reliable and friendly service to our guests and by launching several new industry-leading offerings to provide them even more choice and control.
We also continue to expand our global footprint, adding even more exciting destinations to our portfolio and achieving a record year of room openings. All of this together with our resilient business model translated into solid results. For the full year, we grew RevPAR 60% and adjusted EBITDA 93%. Both RevPAR and adjusted EBITDA were approximately 30% below 2019 peak levels. More importantly, our margins were 500 basis points above 2019 peak levels, reaching roughly 66% for the full year. While some costs will come back in as we continue to recover, we remain extremely focused on cost discipline. Given our asset-light business model and the actions we took during the pandemic, to further streamline our operations, we expect permanent margin improvement versus prior peak levels in the range of 400 basis points to 600 basis points over the next few years.
Turning to results for the quarter. RevPAR increased 104% year-over-year and adjusted EBITDA was up 151%. RevPAR was roughly 87% of 2019 levels with ADR nearly back to prior peaks. Compared to 2019, occupancy improved versus the third quarter with higher demand across all segments. Strong leisure over the holiday season drove US RevPAR to more than 98% of 2019 levels for December. Business travel also improved sequentially versus the third quarter with solid demand in October and November, before the Omicron variant weighed on recovery in December.
For the quarter, business transient room nights were approximately 80% of 2019 levels. Group RevPAR improved 11 percentage points over the third quarter to roughly 70% of 2019 levels. Performance was largely driven by strong social business while recovery in company meetings and larger groups continued to lag.
As we kicked off the new year, seasonally softer leisure demand coupled with incremental COVID impacts due to the Omicron variant tempered the positive momentum we saw through much of the fourth quarter. For January, system-wide RevPAR was approximately 75% of 2019 levels. Despite some near-term choppiness, we remain optimistic about accelerated recovery across all segments throughout 2022. We anticipate strong leisure trends to continue again this year, driven by pent-up demand and nearly $2.5 trillion of excess consumer savings. Our revenue position for President's Weekend is 7 percentage points ahead of 2019 levels and our position for weekends generally is up significantly for the year, both indicated -- indicating continued strength in leisure travel.
Similarly, we expect growth in GDP and non-residential fixed investment, coupled with more flexible travel policies across large corporate customers to fuel increasing business transient trends. As a positive indication of business transient recovery, at the beginning of January, mid-week US transient bookings for all future periods were down 13% from 2019 levels and improved to just down 4% by the end of the month. Additionally STR projects the US business transient demand will return to 92% of pre-pandemic levels in 2022.
On the group side, our position for the year has remained steady as Omicron-related disruption was largely contained to the first quarter of 2022, with most events rescheduled for later in the year. We continue to expect meaningful acceleration in group business in the back half of the year as underlying group demand remains strong. Compared to 2019, our tentative booking revenue was up more than 25%. Additionally, meeting planners are increasingly more optimistic with forward bookings trending up week-over-week since early January.
Overall, we remain very confident in the broader recovery and our ability to keep driving value on top of that. This should allow us to generate strong free cash flow growth and our expectation is to reinstate our quarterly dividend and begin buying back stock in the second quarter. Turning to development. We opened more than a hotel a day in 2021, totaling 414 properties and a record 67,000 rooms. Conversions represented roughly 20% of openings. We achieved net unit growth of 5.6% for the year, above the high end of our guidance, and added approximately 55,000 net rooms globally, exceeding all major branded competitors.
Our outperformance reflects the power of our commercial engines, the strength of our brands, and our disciplined and diversified growth strategy. Fourth-quarter openings totaled more than 16,000 rooms, driven largely by the Americas and Asia Pacific regions. In the quarter, we celebrated the opening of our 400th hotel in China and our first Home2 Suites in the country. This positive momentum continued into the New Year, with the highly anticipated opening of the Conrad Shanghai just last month, marking the brand's debut in one of the world's busiest and most exciting markets.
During the quarter, we also continued the expansion of our luxury and resort portfolios with the opening of the Conrad Tulum and the new all-inclusive Hilton Cancun. With more than 400 luxury and resort hotels around the world and hundreds more in the pipeline, we remain focused on growing in these very important categories. We were also thrilled to welcome guests to the Motto New York City Chelsea, a major milestone for this quickly growing brand and a perfect addition to Hilton's expanding lifestyle category. This hotel exemplifies what it means to be a lifestyle property and incorporates unique and modern design elements and provides guests with authentic and locally-minded experiences. We also celebrated the first lifestyle property in Chicago with the opening of the Canopy Chicago Central Loop and debuted the brand in the UK with the opening of the Canopy London City. These spectacular properties join recently opened Canopy Hotels in Paris, Madrid, and Sao Paulo.
In 2021, we grew our Canopy portfolio by more than a third, year-over-year, opening hotels across all major regions. We ended the year with 408,000 rooms in our development pipeline, up 3% year-over-year, even after a record year of openings. Our pipeline represents an industry-leading 38% of our existing supply, giving us confidence in our ability to deliver mid-single-digit net unit growth for the next couple of years and eventually return to our prior 6% to 7% growth range. For this year, we expect net unit growth to be approximately 5%.
As our guests' travel needs continue to evolve, we again introduced innovative ways to enhance the guest experience. In the quarter, we announced the launch of Digital Key share, which allows more than one guest to have access to their rooms Digital Key via the Hilton Honors app. To further reward our most loyal Hilton Honors members, we introduced automated complimentary room upgrades, notifying eligible members of upgrades, 72 hours prior to arrival. With our guests at the heart of everything we do, we've been thrilled to hear that the early feedback for both industry-leading features has been overwhelmingly positive.
In the quarter, Hilton Honors membership grew 13% year-over-year to more than 128 million members. Honors members accounted for 61% of occupancy in the quarter, just a few points below 2019 levels and engagement continued to increase across members of all tiers. We work hard to ensure that our hospitality continues to have a positive impact on the communities we serve. For that reason, we're incredibly proud to be recognized for our global leadership in sustainability. For the fifth consecutive year, we were included on both the World and North America Dow Jones Sustainability Indices, the most prestigious ranking for corporate sustainability performance.
Overall, I am extremely -- extremely pleased with the progress we've made over the last year, and I'm very confident that Hilton is better positioned than ever to lead the industry as we enter a new era of travel. With that, I'll turn the call over to Kevin to give you more details on the quarter.
