It's the average age of mortality, clearly you're dealing with the mean or mode here. People lived to be 80, 90,100 but that's only part of average lifespan. O

It's the average age of mortality, clearly you're dealing with the mean or mode here. People lived to be 80, 90,100 but that's only part of average lifespan. Once you take out infant and childhood mortality you can see that rising over time.