County Comptroller Phil Diamond announced Monday that Orange County tourist development tax collections crossed $21.5 million in May.

“Summer has just begun and it’s good to see our numbers increasing again. Hopefully this trend will continue throughout the rest of the year,” Diamond said in a press release.

The May 2018 numbers show an improvement of more than 4 percent over May 2017, when the county brought in just shy of $20.5 million in tourism tax collections. The tourist development tax, also known as a resort tax or hotel tax, is a 6 percent tax levied on short-term rentals, mostly hotels and motels.

Most of the money collected via the tax must be used to acquire or operate convention centers, stadiums, auditoriums or museums, or to promote and advertise the tourism industry. A smaller portion of the funds is used for debt service on bonds related to professional sports stadiums.

Tourism tax revenues have beaten their 2017 totals every month this year. The largest year-over-year gain so far came in January, when the $23.7 million collected by the county represented a nearly 15 percent increase over 2017 numbers.

February 2018 numbers were up nearly 9 percent and March 2018 numbers were up nearly 12 percent. April collections were relatively flat compared to a year prior, though the $24.3 million collected still narrowly beat 2017 numbers.