On my 2015 I get about 12,000 miles out of a front tire and 8,000 miles out of a back tire, but I usually run both until I see cords show.
On my 2012 Vetter bike I got about 10,000 miles out of a front tire, and what would have been about 24,000 miles perhaps out of a back tire, but I'd always have the wheel bearings start grinding or popping at around 20,000 miles so the last 2 tire changes were just wheel changes with a new tire installed.
Alan Smith who rides a fully streamlined Ninja 250 also gets about 25,000 miles on a back tire.
I think it's because instead of needing about 15,000 watts to go 75 mph, it only takes about 5,000 watts and you are barely twisting the throttle to maintain highway speeds and so the back tire doesn't have to work as hard to push you through the wind.