It’s pretty self evident, I thought, but sure I’ll look something up. You are right after all, the burden of evidence is on me for making a claim.
https://www.travelandleisure.com/airlines-airports/history-of-flight-costs
Found this on my first google result, I’m sure there are more.
“According to a study by Compass Lexecon, commissioned by Airlines for America, the average flight from L.A. to Boston in 1941 was worth $4,539.24 per person in today’s money, and it would have taken 15 hours and 15 minutes with 12 stops along the way. By comparison, a nonstop flight in 2015 would cost $480.89 and take only six hours.”