So as you can imagine, when you join in the organization, particularly one that has a broad national footprint of retail locations and over 20,000 people in the field, you spend quite a lot of time traveling around the country.
When I think about the 330 franchises in our dealerships, not only do the brands we represent account for 99% of all new vehicles sold in the U.S., but we're also fortunate to have a superbly balanced portfolio of the best automotive brands in the world.
Today, the people of AutoNation have raised over $30 million, which has been plowed into research, treatment and care.
And today, as I already mentioned, we report our seventh consecutive record quarterly results with adjusted earnings per share of $5.76, which is an increase of $137, and revenue increasing by $797 million or 14% compared to the prior year.
Total units for the quarter declined by 1%.
And that was driven by new vehicle sales, down 20%, which was largely offset by an increase in 21% of used vehicle volume compared to the prior year.
When I look at that, nearly 90% of all pre-owned vehicles retailed in the quarter were self-sourced prior acquisition strategy, which obviously includes all of the trade-ins, but now increasingly, our we buy your car program, which processes directly from customers.
And as a result, used vehicle revenue increased 55% for the quarter.
And in November, we opened AutoNation USA Avondale and Phoenix and recently entered the new market with our 10 AutoNation store, USA store in Charlotte.
And we remain on target to open 12 additional new stores over the next 12 months.
I think our focus on margin expense control significantly contributed to our performance as strong new used finance and insurance margin per unit, up significantly year over year and in the quarter, and continued our improvement in our after sales business, which delivered an 11% increase in gross profit.
I know it's been discussed over, the ongoing expense control, something which, frankly, I consider structural in the business now helped contribute to an overall increase in total store profits by over 150%.
Today, we reported fourth quarter total revenue of $6.6 billion, an increase of 14% year over year, driven by impressive growth in used vehicles of 55% as well as double-digit growth in both customer financial services and aftersales.
This was partially offset by a 7% decline in new vehicle revenue due to the continuing supply chain disruption to new vehicles production.
For the quarter, total variable gross profit increased 49% year over year, driven primarily by an increased total variable PBR of $2,026 or 50% increase, with a slight decline in total units of 1%.
As Mike mentioned, 21% growth in used units year over year largely offset a 20% decline in new units over the same period.
We also demonstrated strong growth in aftersales gross profit, which increased 11% year over year.
Taken together, our total gross profit increased 34% compared to the fourth quarter of 2020.
Fourth quarter adjusted SG&A as a percentage of gross profit was 56.7%, a 710 basis point improvement compared to the year ago period.
As measured against gross profit on an adjusted basis, our metrics improved across all key categories, with overheads decreasing 370 basis points, compensation decreasing 230 basis points and advertising decreasing 110 basis points year over year.
Longer term, we expect normalized SG&A to gross profit to be in the mid-60% range, well below our pre-pandemic levels that were consistently above 70%.
Floor plan interest expense decreased to $5 million in the fourth quarter of 2021 due primarily to lower average floor plan balances.
Combined with the lower effective tax rate and fewer shares outstanding, we reported adjusted net income of $380 million or $5.76 per share, a 130% increase year over year.
During the fourth quarter, we closed on the previously announced acquisition of Priority 1 Automotive Group, adding $420 million in annual revenue.
We recently opened our 10th AutoNation USA store in Chile, North Carolina and expect to open 12 more stores over the next 12 months.
Longer term, we continue to target over 130 stores by the end of 2026.
During the fourth quarter, we repurchased 3.1 million shares for an aggregate purchase price of $382 million.
This represents a 5% in shares outstanding from the end of the third quarter.
The company has approximately $776 million available for additional share repurchase at this time.
As of February 15, there were approximately 62 million shares outstanding.
We ended the fourth quarter with total liquidity of approximately $1.5 billion.
And our covenant leverage ratio of debt-to-EBITDA of 1.5 times remains well below our historical range of two to three times.
And if you look at the fourth quarter, we delivered a SAAR around that $13 million from my estimate, well below anyone would have been able to forecast.
And by the way, last year, less than 2% of all the new vehicles sold by AutoNation were above MSRP.
As we see it today, we have over 11 million customers in our family already, and every year, an additional three million interactions.
Gianluca orchestrated a companywide $1 billion digital business building program.
I think demand for vehicles continues to be strong.

Summary:
And as a result, used vehicle revenue increased 55% for the quarter.
Today, we reported fourth quarter total revenue of $6.6 billion, an increase of 14% year over year, driven by impressive growth in used vehicles of 55% as well as double-digit growth in both customer financial services and aftersales.
Combined with the lower effective tax rate and fewer shares outstanding, we reported adjusted net income of $380 million or $5.76 per share, a 130% increase year over year.
I think demand for vehicles continues to be strong.