Of 581 heroin addicts admitted to compulsory drug treatment between 1962 and 1964 nearly half had died by 1997. Of the surviving 242 addicts who were interviewed in 1996-1997 1 in 5 were currently using heroin. This pie chart shows the status of heroin addicts after a 33-year period. The complete data follows:

This second pie chart shows what the status is of the 41.6 percent who were interviewed for a followup. The data follows: