NEW YORK (AP) U.S. home prices fell in October for the 10th consecutive month, posting their biggest monthly decline since early 1991, according to the Standard & Poor's/Case-Shiller home price index.

The record 6.7 percent drop marked the 23rd consecutive month of price deceleration.

"No matter how you look at these data, it is obvious that the current state of the single-family housing market remains grim," said Robert Shiller, who helped create the index, in a statement Wednesday.

The previous record decline was a drop of 6.3 percent, recorded in April 1991.

The S&P/Case-Shiller home price index tracks prices of existing single-family homes in 10 metropolitan areas compared with a year earlier. A broader index of 20 metropolitan areas fell 6.1 percent. Among the 20 metropolitan areas used in the broader index, 11 posted record monthly declines.

Miami posted the largest decline among the 20 markets reviewed. Home prices in the Miami metropolitan area fell 12.4 percent in October compared with the same month last year, surpassing Tampa, Fla. as the worst-performing city. Tampa posted a year-over-year loss of 11.8 percent.

Besides those two cities, Detroit, Las Vegas, Phoenix and San Diego also posted double-digit year-over-year declines.

Atlanta and Dallas, which had previously been posting price appreciation, fell in October compared with a year earlier. Prices fell 0.7 percent in Atlanta and 0.1 percent in Dallas.

Only three areas Charlotte, N.C., Portland, Ore. and Seattle posted year-over-year home price appreciation in October, with Charlotte posting the largest gains at 4.3 percent.

All 20 cities in the broader index posted month-over-month declines, with San Diego posting the largest decline of 2.6 percent.