Auction volume in July was up nearly 4 percent year-over-year, as was year-to-date volume, according to the latest Economic Dashboard prepared by Ira Silver, the chief economist for the National Auto Auction Association.

More specifically, against comparable weeks of 2013, auction volume was up 3.7 percent for July, with year-to-date numbers up 3.9 percent.

Used auto sales fell 1.9 percent in July, but are 0.5 percent ahead year-to-date through July. New-car sales climbed 4.5 percent in July, with yearly figures up 4.3 percent.

Looking at how the auction market has trended in recent years, there were increase in both the number of units that have entered auction lanes and the number of units sold in 2012 and 2013. That is according to the 2013 NAAA Annual Review, which is part of the 2014 Used Car Industry Report from the National Independent Automobile Dealers Association.

Specifically, here is how those numbers played out, as illustrated in the NAAA data:

2011: 13.8 million units enter lanes, 7.7 million sold
2012: 14.5 million units enter lanes, 7.9 million sold
2013: 15.2 million units enter lanes, 8.2 million sold

Conversion rates dipped modeslty from 55.8 percent in 2011 to 54.2 percent in 2012, but they held steady at 54.2 percent in 2013, according to the report.