Where are they getting the 158 million ballots cast number?

I did some quick googling and got these numbers:

According to CNN Trump got 74,222,552 votes and Biden got 81,283,786.

74,222,552 + 81,283,786 = 155,506,338

According to the CFR Trump got 74,222,958 votes and Biden got 81,283,098.

74,222,958 + 81,283,098 = 155,506,056

Those were just the first two sources I checked. Who reported that there were 158 million ballots cast in the 2020 election?

Edit: Mystery solved, the 158 million count is correct! The remaining votes were cast among all the other candidates, including 1,865,724 votes for Jorgensen, and more than a dozen other lesser known presidential candidates. The FEC outlines all the votes cast and who they were cast for here. There is a total at the bottom of that document that reports that 158,383,403 ballots were cast in the 2020 presidential election, But because I am an idiot, I copied all the numbers out and added them myself before saw the document had already done that. So I'ma post that anyway!

81,268,924 + 60,148 + 3,185 + 39,230 + 3,098 + 4,856 + 88,234 + 213 + 1,475 + 6,647 + 405,035 + 1,317 + 409 + 5,403 + 505 + 3,284 + 1,865,724 + 6,791 + 546 + 350 + 815 + 856 + 85,623 + 126 + 2,843 + 1,372 + 1,175 + 49,700 + 29 + 175 + 5,949 + 7,138 + 141 + 1,806 + 74,216,154 + 70,296 + 14,079 + 159,752 = 158383403