The nationwide inventory of residential homes for-sale dropped 21 percent in March compared to a year ago, according to newly released housing data from Realtor.com, tracking 146 metro markets. 

In fact, all 146 markets posted a drop in their inventory, except for two — Hartford, Conn., and Philadelphia. 

The nationwide median list price in March also saw improvement, increasing more than 5 percent last month compared to last year at this time. 

The housing picture is much different than last year at this time, when inventory was up 26 percent and list prices were down 4.81 percent. 

“If the market continues to hold its own, 2012 could well mark the beginning of a broad-based housing recovery,” according to Realtor.com. 

The metros that posted the biggest drops in listings of for-sale homes in the last year are: 

1. Oakland, Calif.: -51.91 percent year-over-year drop in total listings

2. Bakersfield, Calif.: -50.35 percent

3. Phoenix-Mesa, Ariz.: -48 percent

4. Fresno, Calif.: -45.56 percent

5. Miami: -42.34 percent

6. Fort Lauderdale, Fla.: -39.66 percent

7. Seattle-Bellevue-Everett, Wash.: -39.38 percent

8. Atlanta: -39.26 percent

9. Orlando: -39 percent

10. Portland-Vancouver, Ore.-Wash.: -38.79 percent

11. Tampa-St. Petersburg-Clearwater, Fla.: -37.35 percent

12. Stockton-Lodi, Calif.: -36.18 percent