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Hatches and Dispatches
Birth Rate
To plan for population growth planners need to know how many
babies are born each year. Thus they need to look closely at the
birth rate. There are many forms of birth rate. The simplest is
the CRUDE BIRTH RATE (CBR). The CBR in any year is the number of
babies born for that year for every 1000 people in the
population.
| CBR = |
| Total number of births in the
year |
 |
| Mid-year population |
|
x 1000 |
In 1973 the population of Worthing was 89600, and there were
816 births. The town-planner in Worthing finds the CBR like this:
CBR = 816/89600 x
1000 = 9.1
- Use the same method to find the crude birth rate for
Skelmersdale in 1973, given that there were 35 900 people
and 861 babies born. Which town will have to build more
primary schools?
- Work out the crude birth rate for each of the towns and
regions in Table 5.
(Source: Social Trends and
Registrar General's Statistical Bureau of England and Wales)
Table 5 - Births and deaths in towns, regions and the United
Kingdom.
- Write a sentence describing how the crude birth rate in
the United Kingdom has changed during this century.
Death Rate
Planners also need to know how many people die each year The
CRUDE DEATH RATE (CDR) is obtained in the same way as the CBR,
except that it concerns deaths instead of births.
- Copy and complete the following:
The crude death rate (CDR) is the number of ________ in
that year for every _________ people of the population.
- Find out the CDR for Skelmersdale and Worthing in 1973.
In 1973 there were 2272 deaths in Worthing (population 89600).
In 1973 there were 265 deaths in Skelmersdale (population 35900).
- Work out the crude death rate for the towns and regions
in Table 5.
The number of deaths in the United Kingdom increased from 1921
to 1971, but the crude death rate fell during the same period.
- Can you explain this?
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