bottom end starting at near same point in 1974
1 zeta flop by 2045 and properly manufacturable workable for grid storage green batteries by 2050 and decent green batteries by 2060, hover passenger drones by 2085.
mid range where many fit 2020 - 2035.
bottom mid 2035.
decent green batteries ready or nearly ready with at least some green battery option and 1 zeta flop, such a world might not get the hover drones until 2040-2055. This is still quite optimal and is bad but not to bad for global warming with enough care not to do to much damage getting there and quite a commonish outcome.
top mid 2020.
This world would likely have a decent enough green batteries that are just good enough for cars and charge quick enough and would have had green grid batteries in high production for 5 years prior this type of world would likely be smart enough to get hovering passenger drones by 2030-2040. This world in such a setup is less common but still common enough.
achieving 1 zeta flop given the setup by 2005 would be exceptional.
achieving a high optimal dynamic society coded with a very high degree of optimal at 1 zeta flop by 1995 given the setup would be a rare out come indeed.