For the present purpose it is sufficient to connect the rate of marriage with that of births by using as a basis for the former the number of women of conceptive age, or between 15 and 45 years old.
On the other hand, the postponement of marriage in the case of women of conceptive ages is a tendency which seems to be growing in other countries as well as in England and undoubtedly has a depressing effect upon the rate of births.
It is necessary, therefore, to eliminate the difference in the age-constitution of the countries in question by excluding from the field of observation, as before, all except possible mothers, basing the rate upon the respective numbers of women of the conceptive age, that is between 15 and 45.
Here the annual number of legitimate births is shown in its proportion to the mean number of married women of conceptive age at each of the three latest enumerations.
By 1900-1902, however, the rate had fallen in all the larger States by from 23 to 31% and the highest rate recorded, 253 per thousand conceptive wives, was lower than that of any European country except France and Belgium.