UNDATED -- It was an expensive winter for the Minnesota Department of Transportation last season.

The MnDOT winter maintenance report shows the state agency spent nearly $133-million to clear roads and included more than 198,000 hours of overtime.

The report compiles data like costs, winter severity, snow totals and other factors to create a winter severity index score. The score of 154 ended up nearly 40 points higher than the previous season and resulted in the worst conditions for road maintenance crews in a decade.

In addition to 31 snow events and an average snow total of more than 97 inches statewide, hours of freezing rain were up and road and air temperatures were down.

It's the most severe weather since MnDOT began using this tracking system.