The short answer is, we don’t knows for sure, but BlackVault.com and WhoWhatWhy have the first draft of an answer.
Digging deeper, and with the help and verification of Jimmy Falls of the news agency WhoWhatWhy we came up with the same numbers, using two entirely different methods.It confirms there are 3,082 Documents, totaling 217,114 pages that are not yet released to the public.
Source: J.F.K. Assassination Records – The Black Vault
A couple of caveats are in order.