Explain ONE possible reason for the change in the death rate/life expectancy.

a possible reason for the change in life expectancy could be improved life style.

Explanation:

many people tend to die young due to their unhealthy life syles for example when one smokes and drinks alcohol a lot they could die from lung cancer or having too much fatty foods that increase cholesterol that could possibly lead to a possibility of suffering a heart attack and dying decreasing their life expectancy. once one changes their life habits to healthy ones and maintaining them they have a potential of living longer increasing their life expectancy.