I thought this was interesting....
WARNING: Graphic Content! 50 Years of Camaro vs. Mustang Sales Numbers in Living Color
May 20, 2015 at 3:26 pm by Kirk Seaman | Photography by Dick Kelley, Aaron Kiley, Greg Pajo, Robin Riggs, John Roe, and the Manufacturers

When Ford launched
the Mustang in April 1964, it unknowingly fired the first salvo in what would become known as the Pony Car Wars. General Motors, unwilling to let Ford go unchallenged, fired back with the Chevrolet Camaro in September 1966.
The 1967 Camaro met the Mustang in terms of performance, looks, and handling, yet the Ford dominated the sales charts for a decade.
While the cars would jockey for the title over the intervening years, the real winners all along were the enthusiasts. Competition, as ever, improved the breed, with cars that now boast more power and performance than ever could have been imagined some five decades ago.
Note: Click/tap to enlarge the graphic; sales figures are by model year