you can go from 1914 plus 40 years to approx 1935 (helloooo great crowd!!) and from there to 1975 (hellooo 6000 years of man's existence) it's only a hop-skip and a jump to 2015! -ish
Umm 1914 + 40 years would bring you to 1954 1954 + 40 = 1994 1994 + 40 = 2034 Still can't quite figure out where 1975 or 2015 comes into the picture