Tokyo's subway and commuter rail network became one of the busiest in the world as more and more people moved to the area. In the 1980s, real estate prices skyrocketed during a real estate and debt bubble. The bubble burst in the early 1990s, and many companies, banks, and individuals were caught with mortgage-backed debts while real estate was shrinking in value. A major recession followed, making the 1990s Japan's "Lost Decade", from which it is now slowly recovering.