WASHINGTON (AP) — The number of people who signed contracts to buy homes was flat in September, reflecting an ongoing nationwide shortage of homes being listed for sale.

The National Association of Realtors says its pending home sales index was 106 in September, the same as August's revised number. It's the index's lowest point since a 104.7 reading in January of 2015 and 3.5 percent lower than a year ago. It has fallen on an annual basis five of the past six months.

Regionally, the South saw a decline of 2.3 percent while the Northeast, Midwest and West all saw slight upticks. However, all four regional indexes are down at least 2 percent from a year ago, with the South down the most at 5 percent.

Homebuyers — particularly those searching for homes on the lower end of the price scale — are being stifled by rising home values, a limited selection of properties on the market and a shortage of savings. First-time buyers in September were 29 percent of sales, the lowest share in two years, the Realtors said.

Pending sales contracts are a barometer of future purchases. Sales are typically completed a month or two after a contract is signed.