Taxable property values for Sarasota County and its school and municipal taxing districts plummeted last year by more than $20 billion, according to estimates released Monday by the Sarasota County Property Appraiser’s office.

The decreases are as follows: the county, 17 percent; county school board, 12.7 percent; City of Sarasota, 13 percent; City of Venice, 18.3 percent; Town of Longboat Key, 9.8 percent; and the City of Northport, 33.2 percent.

County property appraiser Jim Todora says the losses have mounted largely because the downturn in the real estate market, with homes selling for less.