22 



Eeva Jalavisto 



It comprises 17,986 cases in which the years of birth and 

 death of the children as well as those of their parents were 

 known. The families were therefore completed when recorded. 

 All cases of violent death were excluded. The material goes 

 back to the 16th century, but most of it is from the 18th and 

 the first half of the 19th century. Most cases come from 



35 



%1U 



240 



25-29 30-34 35-39 

 Maternal age, years 



Fig. 1. Percentage of eases in various maternal 



age groups of children born before and after 



1830, respectively. 



Finnish middle-class and noble families, the rest from Swedish 

 middle-class and noble families. The social level is thus rather 

 high. The life expectancy is calculated as mean age at death 

 minus the years lived. 



The time of observation must be at least 100 years if correct 

 values for the entire expectation of life are to be recorded. 

 However, this necessarily implies inconsistency in the material, 

 caused by changing environmental conditions during such a 



