Almost 40% of all urban dwelling space was destroyed during World War II. Although investment in public housing has increased, and credits have been assigned for cooperative and private construction, the housing shortage remained critical five decades later. The average wait for an apartment ranged from 10–15 years. In 1984 there were 10,253,000 dwelling units;4.6% had only one room, 21% consisted of two rooms, 35.5% of three rooms, 25.7% of four rooms, and 13.2% of five or more rooms. An additional 193,000 dwelling units were constructed in 1985. As of 1992, there was a shortage of 1.3 million housing units, a figure that was expected to reach 2.4 million in 2000. About 1.8 million apartments were expected to be lost due to deterioration by 2020.