According to the U.S. Travel Association, Oxford Economics and Ipsos research, more Americans left vacation days unused this year than last.

A total of 768 million vacation days were left on the table, up 9 percent from 2017. Of the unused vacation days, 236 million were forfeited completely, equaling $65.5 billion in lost benefits. More than half of workers, 55 percent, reported they did not use all their available time off.

According to the study, American workers are also earning more paid time off — totaling 23.9 days of paid time off in 2018, when compared to an average of 23.2 days in 2017. This means the number of vacation days American workers didn’t use in 2018 could also be because the number of earned days is increasing, on a steady rise since 2014.

The report also found more than 80 percent of employed Americans claim it’s important to use allotted time off to travel, but don’t actually take a vacation. The most common reason for American workers to not take time off from work to travel is the economic cost, travel hassles and challenges getting away from work.

The research also supports the fact that if Americans used their vacation days, it could result in approximately $151.5 billion in spending, including travel.