"Total drug arrests increased substantially in the 1990s and rose slightly in this decade. There was a large decline in heroin arrests (from 18,000 in 1997 to 6500 in 2006), compensated for by an increase in cannabis arrests. About 80 percent of arrests are for possession rather than dealing. Switzerland makes more arrests (per capita) for simple possession of cannabis than even the United States; comparative figures for a number of countries are provided in Figure S2. However at the other end of the criminal justice system, small numbers are sentenced to incarceration; out of roughly 40,000 persons arrested each year for drug violations, fewer than 2,000 receive terms of incarceration. Moreover the total number of convictions and incarcerations for drug offenses has hardly changed over the period 1990-2006, Fewer than one quarter of those sentenced receive terms as long as eighteen months. The majority of arrests are for possession of cannabis and result in fines of 250-300 CHF; these are not even recorded as convictions."

Source

Peter Reuter and Domenic Schnoz. "Assessing Drug Problems and Policies in Switzerland, 1998-2007." Swiss Federal Office of Public Health. November 16, 2009.