Editor’s note: Data collected and analyzed by Realtor.com through March 2012. Includes single-family homes, condos, townhomes and co-ops.

U.S. housing market trends tracked by Realtor.com show a trifecta of promise: a shrinking number of homes on the market, fresher inventory, and an increase in median list price.

In 146 metros tracked by Realtor.com, the number of for-sale listings was down 21 percent in March compared to a year ago. All but two markets — Philadelphia and Hartford, Conn. — saw listing inventory decline, and 78 markets registered declines of 20 percent or more.

Nationwide, the median number of days a home had been on the market was down nearly 20 percent, to 89 days, and median list price was up 5.6 percent, to $189,900.

Back in March 2011, Realtor.com statistics also showed for-sale listing inventory down about 9 percent from a year ago. But inventory age was up 26 percent at the time.

Data Point	Percent Change, March 2012 vs. March 2011
Number of Listings	-21.48%
Median Age of Inventory	-19.82%
Median List Price	5.56%

Some of the metros in states hit hardest by foreclosures — California, Arizona and Florida — saw the highest drop in for-sale listings over the last year.

The Oakland, Calif., metro area tops the list with a 52 percent year-over-year drop in housing inventory. Not too far away, geographically speaking, the Bakersfield, Calif., metro stands at No. 2 with a 50 percent drop in inventory for the year. Phoenix, Fresno, Calif., and Miami round out the top five, respectively.

The other metros in the top 10, in order, are:

Fort Lauderdale, Fla.
Seattle-Bellevue-Everett, Wash.
Atlanta
Orlando, Fla.
Portland-Vancouver, Ore.-Wash.

As a sign of a shift in the housing market, none of this March’s year-over-year top 10 metros for for-sale listings drops were in last year’s top 10, when Shreveport-Bossier City, La., topped the list with a 47 percent drop, followed by Grand Rapids-Muskegon-Holland, Mich., and Fort Myers-Cape Coral, Fla., respectively.