Party City on Thursday announced it is closing 45 stores nationwide amid a global helium shortage.

The party supplies company did not immediately release a list of which locations will be affected but said the closures will happen throughout the year.

There are 870 Party City stores in the U.S. and Canada and the closures represent about 5 percent of locations.

In a statement, Party City CEO James Harrison said the company usually shutters between 10 and 15 stores annually.

“This year, after careful consideration and evaluation of our store fleet, we’ve made the decision to close more stores than usual in order to help optimize our market-level performance, focus on the most profitable locations and improve the overall health of our store portfolio,” Harrison said.