The number of existing home sales last month rose 2 percent to 5.18 million, slightly more than analysts had expected, the National Association of Realtors (NAR) said Thursday. The increase represents a 12.9 percent bump over the year-ago figure.

Analysts polled by Thomson Reuters had expected, on average, 5 million in May, slightly up from April’s 4.97 million. In April, sales of existing homes rose but remained below the underlying demand because of limited inventory and tight credit, NAR said last month.

Lawrence Yun, NAR chief economist, said the recovery is strengthening and that we should expect limited housing supplies for the balance of the year in much of the country.

“The housing numbers are overwhelmingly positive. However, the number of available homes is unlikely to grow, despite a nice gain in May, unless new-home construction ramps up quickly by an additional 50 percent,” he said. “The home price growth is too fast, and only additional supply from new homebuilding can moderate future price growth.”

Existing-home sales are at their highest level since November 2009, when the market jumped to 5.44 million as buyers took advantage of the tax stimulus. Sales have stayed above year-ago levels for 23 months, while the national median price shows 15 consecutive months of year-over-year increases.