Pushed by growing pre-owned demand and a couple of market conditions making it ripe for consumers to go shopping, used-car sales in the first half of 2015 climbed above 18 million units and beat the year-ago pace by 1.3 percent.

That’s according to a recap released Thursday by the National Automobile Dealers Association, which said there were nearly 4.4 million used sales in June. That compares to 4.3 million used sales in the same month of 2014. Through June, there have been close to 18.6 million used sales, against 18.4 million in the first half of 2014.

“Used-car sales have risen this year because of increased consumer demand. More car shoppers are looking to trade-in and trade up their vehicles,” said NADA chief economist Steven Szakaly. “In addition, trade-in values have held up surprisingly well, and there is currently no sign of weakness in either the new- or used-car market.”

NADA’s sales totals includes figures from franchised and independent dealers, as well as those from private-party transactions.

Year-to-date, franchised dealers are showing the most progress, as their used sales have climbed 2.6 percent. Independents are up 1.9 percent, while private-party sales are down 1.0 percent.

In June, however, independents showed the most growth year-over-year (up 3.6 percent), while franchised dealers were up 2.5 percent and private-party sales climbed 1.1 percent.

Industry-wide, used sales for June were up 2.4 percent.