After TTAC delved into the details of the sixth-generation Chevrolet Camaro’s gradual decline last month, General Motors reported the worst sales month for the Camaro since November 2014.

June 2016 sales of the Chevrolet Camaro fell to a 19-month low. With only 4,969 sales — a huge number by the standards of most sporting cars but a 40-percent drop compared with the Camaro’s five-year June average — U.S. Camaro volume fell below 5,000 units for just the second time in the last 18 months.

Newly launched this past winter, the latest Camaro’s sales have fallen well below the totals achieved by the six-year-old fifth-gen Camaro in its final — and worst — year on the market. In the first-half of 2015, GM reported 42,593 U.S. sales of the Camaro, a 9-percent year-over-year drop. Yet one year later, the new Camaro is down 14 percent to 36,834 units, a drop of 5,759 sales.

GM says that retail consumer demand for the Camaro isn’t falling, but rather it’s increasing. GM’s desire to chop Camaro fleet sales in half, we reported in June, was married to a 13-percent increase in retail demand in the first five months of 2016.

Ford, on the other hand, which sees less harm in providing daily rental fleets with iconic pony cars, sold nearly twice as many Mustangs in June as Chevrolet sold Camaros.

But even the far more common Mustang was down compared with the same period one year ago. June 2016 Mustang volume dropped 17 percent to 9,776 sales. Year-to-date, compared with its first full year in sixth-gen form, U.S. Mustang volume is down by 5,325 sales.

The Mustang wasn’t the only Detroit coupe to outperform the Camaro in June. Like the Camaro and Mustang, Dodge sold fewer Challengers in June 2016 than in June 2015. Challenger sales slid by a fifth to 5,479 units.

GM, of course, does have in its quiver another surprisingly high-volume sports car. Chevrolet Corvette sales are falling in 2016, not an unexpected turn of events given the massive figures achieved by the two-seater last year. But GM nevertheless added 2,483 Corvette sales to the Camaro’s tally in June; 14,668 in the first-half.

No high-end sports car sells anywhere near as often as the Corvette in the United States. A bundle of European sports cars – 4C, TT, Z4, F-Type, SLK, Boxster, Cayman – combined for fewer than 10,000 U.S. sales through the first six months of 2016. Porsche sold 5,026 911s. Dodge sold 298 Vipers.

[Images: GM, Ford]

Timothy Cain is the founder of GoodCarBadCar.net, which obsesses over the free and frequent publication of U.S. and Canadian auto sales figures. Follow on Twitter @goodcarbadcar and on Facebook.