No. 5: San Jose-Sunnyvale-Santa Clara, Calif.

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No. 5: San Jose-Sunnyvale-Santa Clara, Calif.

Average monthly rent: $1,590
Annual drop: -12.3%
Q4 2009 drop: -2.3%

Renting an apartment in Silicon Valley got a little cheaper as the vacancy rate increased to 5.3% last year. The number of unemployed reached 103,300 people, or 11.5% of the population in December, according to the BLS, compared to 7.8% in 2008. This affected the commercial segment as well: According to KGO-TV, the city’s office-space vacancy rate is nearly 25%.