Has the number of Knight/Year of Plenty/Road Building/Victory Point/Monopoly cards in Settlers of Catan's development card deck evolved across editions, or is the latest edition the same as the first?
If so, what was its progression?
It has stayed the same from the beginning (though Mayfair has changed some rules and the map in the last edition):
I've seen no indications of changes by edition, but note that Cities and Knights alters it.
As I recall, my copy of the original Mayfair 4-player edition (with the teeny tiny cards) combined the Kosmos 4-player and 5-6 player decks, and that was fixed when Mayfair started using the Kosmos materials in later editions. It's possible I just had a bad copy, though.