HDSS Fertility Data

The available indicators are crude birth rate (CBR), Age-specific fertility rates (ASFR), Total fertility rate (TFR), Mean age at childbearing (MAC) and Sex ratio at birth (SRB)
Fertility is measured using the number of births to HDSS female residents aged 15 to 49 .
Crude birth rate (CBR)
CBR is the number of births divided by the person-years of all ages, expressed in births per 1000 person-years. 
NB: CBR depends on age-structure, which evolves from one calendar year to the next and from one HDSS to the other. Therefore CBRs are not strictly comparable over the period and across HDSS.
Age-specific fertility rates (ASFR)
ASFR is the number of births in a specific age-group divided by the person-years lived in that age-group, expressed in births per 1000 people. The seven age-groups are 15-19, 20-24, 25-29, 30-34, 35-39, 40-44, 45-49.
Total fertility rate (TFR)
TFR is the sum of ASFR multiply by 5. It is interpreted as the mean number of births that a hypothetical cohort of women would have had by experiencing the fertility conditions of a particular calendar year over its lifetime.
Mean age at childbearing (MAC)
MAC is computed as the sum of age-specific fertility rates (ASFR) weighted by the distribution of females at the mid-point of each age group as per the life-table estimate, divided by the sum of the age-specific rates. It is interpreted as the mean age of mothers at the birth of their children if women were subject throughout their lives to the age-specific fertility rates observed in a given year. 
Please note that the MAC computed for INDEPTHStats is not the standard MAC as found in textbooks, since it is weighted using the distribution of women by age as per the life-table estimate. 
Sex ratio at birth (SRB)
SRB is the number of male births divided by the number of female births, expressed in male births per 100 female births.