A barren supply of deeply discounted foreclosures has dragged Seattle-area home sales to its slowest pace in 15 years for the month of May. Nonetheless, median sales prices ticked up slightly. According to a report from MDA DataQuick, a San Diego-based firm that tracks real estate data across the nation, 3,142 new and resale homes changed hands in May for the Seattle-Tacoma-Belleveu metropolitan triangle. It’s a 13.5% increase from April, but down 21.7% from May of last year. It was the slowest May since 1994 and continues a string of 36 consecutive months of a year-over-year sales fall. Seattle foreclosure sales are not yet at the levels of other western markets, where bargains are lush and sales growing. It makes up 19.2% of Seattle’s transactions – down 21.8% from its peak in February 2009. On the other hand, the region’s overall median sales price climbed from April, and faltered by only 11% from a year ago, according to the DataQuick report. The median sales price paid for new and resold homes in the Seattle area was $308,000, a 1% gain from April but a drop by 10.7% from last year. Seattle’s peak came in June 2007 at $365,200. But the decline from last year is not as severe as other major U.S. markets, researchers said in the DataQuick report. Down the coast, Southern California homes have seen a drop of 32.7%, and Las Vegas experienced a 43.7% fall. Write to Jon Prior.