<Tr> <Td> 2014 world average </Td> <Td> 71.5 </Td> <Td> </Td> </Tr> <P> Life expectancy increases with age as the individual survives the higher mortality rates associated with childhood . For instance, the table above listed the life expectancy at birth among 13th - century English nobles at 30 . Having survived until the age of 21, a male member of the English aristocracy in this period could expect to live: </P> <Ul> <Li> 1200--1300: to age 64 </Li> <Li> 1300--1400: to age 45 (because of the bubonic plague) </Li> <Li> 1400--1500: to age 69 </Li> <Li> 1500--1550: to age 71 </Li> </Ul> <Li> 1200--1300: to age 64 </Li>

What is the average length of a human life