2015 the suspected in-country overstay rate was under 1% at .9%. DHS was able to confirm that 99% of individuals who entered the US on non-immigrant visas set to expire in 2015 have departed the US.
For individuals who entered on the visa waiver program the overstay rate in 2015 was a mere .6%. Granted, 6% is still ovevr 150,000 people that are unaccounted for. It is impressive that what large percentage of individuals respect the law and return in a timely manner.
Bhutan citizens have the highest overstay rate at 24.89%. The actual number of overstays from Bhutan is rather low at 110 people.
Solomon Islands citizens had a perfect record with 0 overstays in 2015. 140 citizens of of the Solomon Islands came to the US and 140 left. Sao Tome and Principe also had a perfect record with a 0% overstay rate.
Pursuant to the requirement contained in Division F, Title I of P.L. 114-113, the Consolidated Appropriations Act, 2016, and 8 U.S.C. 1376, DHS must publish data regarding visa overstays.FULL REPORT HERE.