New numbers from the National Association of Realtors show that, even as the summer market looked to be slowing down, homes for sale were still selling quickly. In fact, the typical property was only on the market 17 days in August and 87 percent of homes sold during the month were available less than 30 days. It’s yet another sign that inventory remains the market’s biggest issue. Lawrence Yun, NAR’s chief economist, says home buyers are still looking, despite challenging conditions. “Although there was a decline in home purchases, potential buyers are out and about searching, but much more measured about their financial limits, and simply waiting for more inventory,” Yun said. The lack of homes for sale has made for a competitive and fast-paced summer. It’s also held back sales. In August, sales of previously owned homes fell 2 percent from the month before. The decline came after two consecutive months of gains.