Department of Homeland Security: H-1B and L-1A Compliance Review Site Visits Fraud Detection National Security Compliance Review Data (October 1, 2011, to September 30, 2015) (Fiscal Year 2016 Report to Congress) [open pdf - 616KB]
"This report responds to the Senate Appropriations Committee's request for information on H-1B1 and L-1A2 compliance review site visits under the Administrative Site Visit and Verification Program. The report includes totals, localities, and outcomes of site visits, and the number of site visits that warranted referrals to U.S. Immigration and Customs Enforcement (ICE). USCIS's [U.S. Citizenship and Immigration Services] Fraud Detection and National Security (FDNS) Directorate conducts H-1B and L-1A site visits under the post-adjudication compliance review process. This report covers H-1B and L-1A site visits conducted from October 1, 2011, to September 30, 2015. During the past 4 years, FDNS conducted a total of 48,109 H-1B and 2,473 L-1A site visits."
U.S. Department of Homeland Security: http://www.dhs.gov/