In the Interview with the Dunmer, the old Legionaire indicated a lifespan of 120 - 140 is typical for a Dark Elf. It's certain wizards and necromancers can extend their lifespan unnaturally, but the average Dunmer doesn't even see 200 years.
Altmer are said to live 100 years longer than other Elves because a culture hero named Phynestar taught them to walk with a shorter stride. Since the only other age range we have for any elf is 130 years for Dunmer, and it's never implied the Dunmer have a lower than normal lifespan, we can assume Altmer can live up to 230 years if they're not a sorcerer or necromancer.
I would imagine Bretons, being mostly mannish with only a little Elven ancestry, would live maybe 5 to 10 years longer than the average human if there's any increase at all. Again, wizards are an exception. Wizards are an exception for any race, period. It's implied that Janus Hassildur is believed to be very old due to sorcery. Of course you and I know he's a vampire but the average Imperial citizen is clueless about that. Since it's so widely accepted that sorcery could account for his extreme lifespan and vitality, we can assume an Imperial can live for centuries with life extending magic.