Not a distribution, but probably a useful data set, is the first year a particular grade was climbed. http://web.stanford.edu/~clint/yos/hard.htm http://web.sta

Not a distribution, but probably a useful data set, is the first year a particular grade was climbed. http://web.stanford.edu/~clint/yos/hard.htm http://web.stanford.edu/~clint/yos/hard.htm For an approximation of what you're after, I'd recommend comparing number of first ascents of climbs of a particular grade in the last 3 - 5 years. This time frame should include enough data to get a reasonable answer, and won't be too biased by advances in equipment and ability over the last few decades. The Crag (http://www.thecrag.com http://www.thecrag.com) have an API that may be useful for an initial data set (http://www.thecrag.com/article/api http://www.thecrag.com/article/api). Other online resources are http://www.8a.nu http://www.8a.nu and http://www.supertopo.com/ http://www.supertopo.com/ but I don't think they have easily accessible APIs.