Average time that seeds will last?

This is one of those questions that gets so many answers but I ask because I have sprouted some bag seed from 1984 which is in the 30 year range, is that crazy or has anyone been able to sprout much older beans?

Ive heard of people getting really old seeds from the 70s/80s to germinate. really just depends on how they were stored. Only one way to find out!