China has an acute shortage of housing, attributable not only to the large annual increases in population (over 10 million a year) that must be accommodated but also to the long-standing policy of directing investment funds into heavy industry rather than into housing and other social amenities. In the mid-1990s, the total number of housing units in China stood at 276,502,000. Approximately 400,000 new dwellings were completed per year and 90.6% of all homes had piped water. By the end of 2002, an additional 19.25 million square meters of commecrcial housing had been completed, presenting a 10.5% increase from the previous year. The government expects to build 486 million to 549 million square meters of floor space each year for the first 20 years of the 21st century. In 2002, the annual investment for housing was at about US $97 billion. During the 1990s, the government began a program of transferring ownership of state-owned housing into private hands at fairly low costs and with subsidized mortgages. As a result, an estimated 73% of families own their own residence.