The FBI says more than two million Americans have lost or misplaced their keys.

It said on Friday that a total of 8.7 million of those lost keys were locked in cars in the U.S. The bureau said the keys were stolen between June 2 and June 16, 2016, and about 400,000 keys were recovered in the span of that period.

The FBI said in a statement that it was not immediately clear how many keys were lost or stolen, and that its analysis did not include cases where the keys had been returned or were lost.

FBI said that while the bureau has not identified all the keys it recovered, the vast majority of the keys used to unlock cars were locked.

“We have not seen an increase in lost or lost-locked keys in the last six months,” the FBI said.

The bureau said it would release more information about how it determined which keys were being lost or recovered, including how many had been used, how long they had been in use, and how many people had lost or forgotten their keys in a given time period.