Quotas were repeatedly set and raised, and conscription took place without regard to health or work experience - mines became staffed with office workers, craftsmen and students with no mining experience. By 1948 workers were pulled away from factories and criminals from jails to staff the mines, as were POWs returning to Germany from the Soviet Union. Housing lagged behind the burgeoning workers (with many regions doubling in population between 1946 and 1951), worsening already difficult conditions.