FOIA REVEALS USCIS STATISTICS ON P PETITIONS FOR F
"USCIS released records on 4/18/17 in response to a FOIA request for statistics on initial P petitions and extension requests, including numbers received, approved and denied at both the CSC and the VSC. The records cover P petitions from FY2011 through FY2016."
http://www.aila.org/infonet/foia-reveals-uscis-statistics-on-p-petitions