 Sentences under re @-@ education through labor were typically for one to three years , with the possibility of an additional one @-@ year extension . They were issued as a form of administrative punishment by police , rather than through the judicial system . While incarcerated , detainees were often subject to some form of political education . Estimates on the number of RTL detainees on any given year range from 190 @,@ 000 to two million . China Daily in 2007 estimated that there were a total of 310 re @-@ education centers in China at that time . 
