James Comey. Alex Wong/Getty Images The FBI's announcement reaffirming that it won't pursue criminal charges against Hillary Clinton came too late for nearly 24 million voters.

That's how many people used early voting to cast ballots while the FBI reviewed the emails of a Clinton aide.

FBI Director James Comey revealed the review of the new emails on Oct. 28, at the height of early voting. That upended the presidential race at a time when Clinton was building a lead.

On Sunday, Comey informed Congress that the review was completed and the FBI stood by its decision not to pursue charges.

The nearly 24 million voters who voted during those nine days represent about 18 percent of the expected total votes for president.

As of Monday, at least 42.5 million total ballots were cast early.