Page 62 - Niên giám 2021

Sex ratio of the = Total of males × 100
population Total of females

Crude birth rate: The indicator measures the fertility of the population,
is one of the two components of natural population increase. High or low value
of crude birth rate can affect the size, structure and population growth rate.
Crude birth rate indicates that for every 1000 people, how many live births are
in the reference period.

CBR = B  1000
P
Where:

CBR: Crude birth rate;

B: Total live births in the reference period;

P: Population up to the reference time-point.

Total fertility rate (TFR) reflects the average number of live births that
would be born per woman (or a group of women) during the childbirth period
if the woman (or a group of women) passes age-specific fertility rates observed
in a given reference period during the reproductive period (aged 15 to 49).

In case the specific fertility rates are calculated by age groups (age-interval
of each group is 5 years) then index “i” expresses 7 age groups, including: 15-
19, 20-24, 25-29, 30-34, 35-39, 40-44 and 45-49. Total fertility rate is
calculated by the following formular:

7 B
TFR = 5  i  1000
i= 1 W i

Where:

TFR: Total fertility rate;
Bi: Number of live births in the reference period of women in the age group (i);

th
i: i age group;
th
Wi: Number of women of the i age group up to the reference time-point.

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