By a 2010 study by the National Police Agency illegal residents decreased from 219,000 in 2004 to 113,000 in 2008, and in addition, the number of arrested foreign visitors decreased from 21,842 in 2004 to 13,880 in 2008. The percentage of foreign nationals in all arrestees charged in penal code crimes was about 2.0% and this number has remained relatively stable. While the percentage of foreign nationals among all arrestees charged in cases involving robbery or burglary was around 5.5% in 2008.