Fuel Economy, Again

[radare]

I was updating my Fuelly account with my most recent fill-ups on the red bike, from the Phantom Canyon ride, and I noticed that both bikes have about the same average, 55-56 mpg. I've had tanks as good as 65mpg and as bad as 51mpg. I am seeing this consistently on both the stock bike and the modified bike.





I run synthetic oil, Yamaha-recommended tire pressures, 91-octane fuel and live at 5,280' above sea level. Both bikes are jetted the same; #20 pilot jets and #100 main jets. Float heights are set to 7mm, dry. Both bikes have stock intake and exhaust systems. I tend to ride the black one a bit more aggressively.

What I'm wondering, and the point of htis post is, why am I seeing these numbers and so many others are reporting numbers in the high 30's? Thoughts?