There are 147 FBI agents involved in the Hillary Clinton email investigation - The Washington Post

Writing about the FBI’s investigation of Hillary Clinton’s email this morning, a political blogger named Chris Cillizza unleashes this parenthetical zombie:

(Worth noting: Lots of other secretaries of state used private email accounts to supplement their official accounts; none used only a private email account and server.) 

“Lots of other secretaries of state” who used private email accounts are, in reverse chronological order, (possibly) John Kerry, Condoleezza Rice, and Colin Powel. For the record. The other 64, plus a dozen or so acting, going all the way back to John Jay, did not.

Here's the relevant discussion from a Politifact article on the subject dated March 8th, 2015:

While it may be hard to remember a time before email, only four former secretaries have held the job during the prominence of electronic communications: Clinton, Condoleezza Rice, Colin Powell and Madeleine Albright.…According to MSNBC, an aide for Albright said she "did not use email while she was in office" from 1997 to 2001.

Doesn’t look like a whole lot of lots to me.