Finland underwent severe economic depression in 1990–93. Badly managed financial deregulation of the 1980s, in particular removal of bank borrowing controls and liberation of foreign borrowing, combined with strong currency and a fixed exchange rate policy led to a foreign debt financed boom. Bank borrowing increased at its peak over 100% a year and asset prices skyrocketed. The collapse of the Soviet Union in 1991 led to a 70% drop in trade with Russia and eventually Finland was forced to devaluate, which increased the private sector's foreign currency denominated debt burden. At the same time authorities tightened bank supervision and prudential regulation, lending dropped by 25% and asset prices halved. Combined with raising savings rate and worldwide economic troubles, this led to a sharp drop of aggregate demand and a wave of bankruptcies. Credit losses mounted and a banking crisis inevitability followed. The number of companies went down by 15%, real GDP contracted about 14% and unemployment rose from 3% to nearly 20% in four years.