1988: The Stasi employed a work force of 102,000 to monitor a population of 17 million: one secret policeman for every 166 East Germans, compared with one Gestapo official for every 2000 citizens under the Third Reich and one KGB agent for every 5830 people in the Soviet Union. In addition, the Stasi had at least 174,000 regular informers among the population, 10,000 of whom were under the age of 18. There was one Stasi employee or regular informer for every 66 people; if part-time informers were included, the ratio of agents and informers to citizens may have been one to 6.5.
Source: John O. Koehler, Stasi: The Untold Story of the East German Secret Police (1999), pp. 8–9