Not sure 40 years is a fair number to use:<p>[S]ix years after finishing college, 57 percent of computer science graduates are working as programmers; at 15 years the figure drops to 34 percent, and at 20 years — when most are still only in their early 40’s — it is down to 19 percent. In contrast, the figures for civil engineering are 61 percent, 52 percent and 52 percent.<p><a href="http://www.businessinsider.com/better-to-be-a-software-engineer-than-a-pro-athlete-2017-1?r=UK&IR=T" rel="nofollow">http://www.businessinsider.com/better-to-be-a-software-engin...</a>