A long term measure of this trend is the "total fertility ratio
" (TFR)--the average number of children born per woman during her lifetime.
The theory implies that a high sex ratio is positively associated with the proportion of women who marry and the fertility ratio
and negatively associated with women's age at marriage, female literacy and labor force participation.
According to survey report over 38,02,928 infants born in a year and fertility ratio
among women between 15 years of age to 19 years has been 01,46,425/ while among the women between 20 to 24 years of age fertility strength has been 10,05,337, where as among the women between 25 years to 29 years fertility ratio
has been 12,38,000 and between 45 to 49 years old women this strength has been estimated up to 47,913 children per year.
More than a decade ago, Smith and colleagues demonstrated that an increase in the proportion of black women who were unmarried accounted for the overwhelming share of the increase in the black nonmarital fertility ratio
. (8) Between 1983 and 1992, for example, the black NMFR rose by 10 percentage points, from 59% to 69%.
The current total fertility ratio
(TFR = number of children given birth per woman) is only 1.26, which is the lowest among leading industrialized countries, including the United States and Europe.
An observed rise in the nonmarital fertility ratio
(i.e., the proportion of all births that occur outside of marriage) among blacks can be explained almost completely by declines in marriage.
Vitamin D deficient male rats had 45 % reduction in successful mating indicating lower fertility ratios
with a few abnormal pregnancies and deliveries in females.
"A Decomposition of Trends in the Nonmarital Fertility Ratios
of Blacks and Whites in the United States 1960-1992." Demography 33, 1996, 141-51.
Remember, they have already been around longer than you have, so don't doubt they are more tolerant than you are of freaky weather patterns, droughts and floods, and soil depths and fertility ratios
. Notwithstanding the damaging exotic insects and diseases which we have introduced to our native plants, for the most part our native plants are better adapted to shun the adverse effects of native organisms that bug them.
Single plant lineages were maintained when assessing fertility ratios
The high fertility ratios
and the large numbers of children from these areas have intensified pressures in placements in the already crowded urban environments of the nation.
A decomposition of trends in the non-marital fertility ratios
of blacks and whites in the United States, 1960-1992.