220k ft over 5800 miles for 38 ft/mile. Back when I lived in Indiana, it ranged from 14 to 19 ft/mile. I expect those years when I managed 19, I rode a fair number of miles in Kentucky.
I should extract the data for the 11 months I lived in west Texas, where I had to ride 10 miles from home to find anything remotely resembling a climb. But if I had a measure of headwind miles, west Texas would be killer.