Before the vaccination and modern medicine, we had a lifespan of 16 to 17 years.
I think world history would look a little different if it had been entirely forged by hormonal brats on the verge of carking it. Your figures might be a little off.
Throughout most of history, the average life expectancy was around 30 years...
But, that is mostly due to infant mortality rates... anyone surviving into adulthood was expected to live 60+ years... not much different from today really