How has the price of film processing developed over the years?

Factual Questions
1

How has the price of getting film processed changed over the years, in real dollars or pounds?

Excluding things like getting black and white developed at most labs being considerably higher due to no more machines so they have to do it by hand, you can still send it off to ILFORD or Rollei in their developing envelopes.

2

Some random prices per print in US cents pulled from the ol’ shoeboxes:

20 1996
17 1987
23 1980
32 1965 (B&W)

I think things got seriously automated in the 80s, but still about as reliable as a stockbroker’s advice.