The number of vacant homes in the U.S. increased to 19 million in the first quarter 2010, reported the Department of Commerce's Census Bureau. In addition, the nation's homeownership rate declined to 67.1%, its lowest level since Q1 2000, as shown by these graphs on Calculated Risk.

Though the number of housing vacancies increased, the rental vacancy rate (10.1%) and the homeowner vacancy rate (2.6%) both fell .1 percentage point from last quarter's rates.

In the past year, the housing inventory has risen by 1.14 million to 130.9 million, while occupied homes have increased by 1.07 million to 111.9 million, according to the Census Bureau's report.