EARLY ROMAN MIDDLE BEFORE 1900 1953-55 



1R0N& EMPIRE AGES 1789 U.S.A. NETHER 



BRONZE England MASS. -LANDS 



AGE a N.H. 



Figure 3. — Life Expectancy Over the Ages 

 Life expectancy at birth is believed to have been about 18 years in prehistoric times. It 

 has quadrupled today in some of the Western industrialized countries. (Source: Length of 

 Life: A Study of the Life Table, by Louis L Dublin, Alfred J. Lotka, and Mortimer Spiegel- 

 man and ref. 15 A.) 



672-174—63 41 559 



