Scott Nearing[125] says that the years from 45 to 60 or 65 should be the most valuable ones from the social point of view. He reminds us that if the average length of life were doubled the population would in a generation double without any increase in the birth rate. The average length of life in the leading countries of the world varies much. In Sweden, for males it is 53.9; France, 45.7; England and Wales, 44.1; Massachusetts, 44.1; India, 23.0. Men born in America of native white parents live on the average only 31 years; those born of foreign white parents, 29.1 years. Men in the modern cities die when they are one score and ten. There is a great difference in occupations: for shoemakers the death rate per thousand is 8.7; farmers, 11.02; tailors, 13.65; cigar and tobacco makers, 21.67; servants, 21.78; and laborers, 22.3. Such figures suggest the dangerous occupations. As to the length of the working life, from 15 to 65, out of every one thousand males living at the age of 15, 440 will survive to the age of 65, while the rest will have fallen out for some cause. So society has lost more than half its working force at the end of the working period. In the 16th century the average length of life he estimates at 21.2 years; in the 17th, 25.7; in the 18th, 33.6; and in the 19th, nearly 40 years. Finkenberg thinks that in the 16th century it was between 18 and 20 years; at the close of the 18th, over 30; while to-day it is from 38 to 40. We have no data for the United States as a whole that are of any value. Among males in England the average length of life is increasing at the rate of 14 years per century; France, 10; Denmark, 25; Massachusetts, 14. Although these figures are only approximations, Nearing thinks life is probably twice as long as it was a few centuries ago.