[quote=Truth]
What lifespans are you willing to accept for Bosmer, Dunmer, and Altmer? I ask this because as far as I am able to find, there is not a set lifespan for any of the three.
[/quote]

"According to the Elder Scrolls Online "Ask Us Anything" Forum [1], elves of all three kinds (Bosmer, Dunmer, Altmer) live about two or three times longer than the other races (humans, Orcs, Khajiit, and Argonians). A 200 year old elf is old, a 300 year old elf is very old. Anyone older than that has prolonged their life through powerful magic."

Found this, hope it helps.