Uhm,

(1) I measured up to 1960. Since then it's a 61 year period, not a 25 year one.

(2) That period having "two world war" versus our "stability" makes my point even more. One would expect a period without 2 world wars bothering it, and with stability to enjoy, to produce more.

(3) "and the development of modern physics and engineering" that's my point exactly. That we enjoyed the low hanging fruit of that development and now we've stagnated and get much less impressive feats.