That has never been more important than it has been over the last 16 months, and I'm proud of the results we have delivered.
Sales for the year decreased 20% from $2.07 billion to $1.65 billion, and our adjusted diluted earnings per share from continuing operations decreased 39% from $2.15 per share to $1.31 per share.
As such, I'm particularly pleased to report that sales for the fourth quarter were up 5% from $417 million to $438 million, and I'm even more pleased to report that adjusted diluted earnings per share from continuing operations were up 81% from $0.26 per share to $0.47 per share.
Our sales to commercial customers increased 3%, and our sales to government and defense customers increased 7%.
Sequentially, our total sales growth was 7% and our adjusted diluted earnings per share growth was 27%.
The earnings per share growth was driven by our operating margin, which was 5.2% for the quarter on an adjusted basis, up from 3.2% last year and 5% in the third quarter.
It was another strong quarter, as we generated $23.5 million from operating activities from continuing operations.
Excluding the impact of that AR program, our cash flow from operating activities from continuing operations was $33.3 million.
We were awarded a follow-on contract from the Navy that extended and expanded our support of its C-40 fleet.
We entered into a 10-year agreement with Honeywell to be an exclusive repair provider for certain 737 MAX components.
And most recently, we signed a multi-year agreement with United to provide 737 heavy maintenance in our Rockford facility.
Finally, we focused on our balance sheet and working capital management, which allowed us to generate over $100 million of cash from operating activities from continuing operations, notwithstanding the investments that we made to support new business growth.
Our sales in the quarter of $437.6 million were up 5% or $21.1 million year-over-year.
Sales in our Aviation Services segment were up 6.5%, driven by continued strong performance in government, as well as the recovery in commercial.
Gross profit margin in the quarter was 16.4% versus 8.7% in the prior year quarter.
And adjusted gross profit margin was 16.5% versus 13.6% in the prior year quarter.
Aviation Services gross profit increased $32.9 million, and Expeditionary Services gross profit increased $2.5 million.
Gross profit margin in our commercial activities was 13.4%.
Gross profit margin in our government activities was 19.7%, which was driven by continued strong performance as well as certain events that occurred during the quarter.
The adjustments in the quarter include $2.1 million related to the closure of our Goldsboro facility, which had supported our Mobility business within Expeditionary Services.
As a result, we expect to recognize impairment charge of between $5 million and $10 million in the first quarter of fiscal '22.
These activities, along with the terminated contracts I just described, collectively contributed approximately $140 million of annualized pre-COVID sales, which will not return as commercial markets recover.
SG&A expenses in the quarter were $48.8 million.
On an adjusted basis, SG&A was $46.7 million, up only $0.2 million from the prior year quarter despite the increase in sales.
We continue to focus on driving SG&A as a percent of sales to 10% or lower as our top line recovers.
As John indicated, we generated cash flow from our operating activities from continuing operations of $23.5 million as we continued to reduce our inventory balance.
In addition, we reduced our accounts receivable financing program by $9.8 million in the quarter from $48.4 million to $38.6 million.
As a result, our balance sheet remains exceptionally strong with net debt of $83.4 million versus $197.3 million at the end of last year.
And our net leverage as of year-end was only 0.7 times.
On the government side, which has been very strong for us, we do expect a moderation in the pace of growth as buying under previous administration normalizes and some of our programs come to a natural completion, such as the C-40 aircraft procurement program for the Marine Corps, but the valuable past performance that we have continued to build and the cost reduction actions that we've taken put us in a strong position to continue to take market share, and our government pipeline remains strong.

Summary:
As such, I'm particularly pleased to report that sales for the fourth quarter were up 5% from $417 million to $438 million, and I'm even more pleased to report that adjusted diluted earnings per share from continuing operations were up 81% from $0.26 per share to $0.47 per share.