True statement about 'total fertility rate' is -

Total fertility rate Total fertility rate represents the average number of children, a woman would have if she were to pass through her reproductive years, bearing children at the same rates, as the women now in each age group. It is computed by summing the age specific fertility rates for all ages. It gives the approximate magnitude of the completed family size. Total marital fertility rate Average number of children that would be born to a married women. If she experiences the current fertility pattern throughout her reproductive span.