The average US employee who receives vacation/paid time off has only taken about half, 54%, of his or her eligible vacation time/PTO in the past 12 months, according to a survey released by Glassdoor.

This is relatively consistent with the 51% of vacation time employees reported taking in 2014, when Glassdoor first conducted this survey. However, almost two-thirds of employees, 66%, report working while on vacation, up from 61% three years ago.

Of employees who receive vacation/paid time off, 91% report taking at least some time off in the last 12 months, up from 85% in 2014. Over the same time period, 23% reported using all of their eligible time off, while another 23% reported taking 25% or less of their eligible time off — both down two percentage points from 25 percent in 2014.

Nine percent reported taking no vacation or paid time off at all.

Despite slightly more employees taking vacation time overall, fewer employees who take vacation/paid time off report being able to completely “check out” while they are on vacation — 54% in 2017, down from 63% in 2014 — and 27% are expected to stay aware of work issues and jump in if things need their attention while they are away, up from 20% in 2014.

“We are seeing a push and pull situation when it comes to employees taking vacation and paid time off, in which people attempt to step away from the office for a break from work, but technology is keeping them connected with the swipe of a finger,” said Carmel Galvin, Glassdoor’s chief human resources officer. “While taking a vacation may make employees temporarily feel behind, they should realize that stepping away from work and fully disconnecting carries a ripple effect of benefits.”

The online survey was conducted within the US by Harris Poll on behalf of Glassdoor from March 30 to April 3, 2017. The survey included 2,224 US adults, among which 1,209 are employed, 852 receive vacation/paid time off, and 771 took vacation/paid time off in the past 12 months.