1957 - United Nations Statistics Division

tabulation, i.e., by date of occurrence or by date of registration.
The symbol of a dagger (t) is used to indicate
countries which tabulate by date of registration.
The exclusion from some series of deaths of infants
who die before their births are registered and who are
thereby counted only as stillbirths or as "presented without
life" may contribute to the lack of comparability,
both of total deaths and deaths under one year. 30
Because these data are classified according to age, they
are subject to the same inaccuracies of age reporting
described in connexion with population (see p. 17) . The
factors governing the inaccurate reports may be somewhat
dissimilar because of the differences in the method of
taking a census and registering a death, but, in general,
the same errors can be observed. As in census tabulations,
the absence of frequencies in the unknown age group
does not necessarily indicate complete age reporting; it
may also be an indication that the "unknowns" have
been eliminated, either by assigning an age before tabulation
or by proportionate distribution after tabulation.
Table 11
Death rates specific for age and sex are presented in
Table II. In general, rates are for the period beginning
1948 to provide continuity with the previous trend of
age-sex specific death rates published in the 1951 Demographic
Yearbook.
The age classification used is the same as that for Table
10, except for the elimination of the unknown age category.
An initial age class of "under 1 year" is followed by
"1·4" and 5-year age groups to 80-84. A residual terminal
group of "85 years and over" completes the classification.
Deviations from these categories are shown in the table
by consolidation bars or new run-in box-heads.
Coverage: A total of 104 geographic units are able to be
included in this table despite the fact that an acceptable
population base corresponding to the age and sex classification
of the deaths was required. "Acceptability" in
this case implies corresponding geographic and population-group
coverage and the same age classification.
Further, the estimate must be the result of an enumeration
or be based on an enumeration adjusted in time by
the use of vital and migration statistics. Distributions
estimated by the pro-rating method of applying to the
total the percentages of population in each age group at
the time of the census are not used.
Rate computation: Each rate is the number of deaths that
occurred within a given age-sex group during the course
of a year, per 1,000 persons falling within that age-sex
group at the middle of the year or at some other date
within the year. The populations used are those which appear
in Table 4. Deaths at unknown age and the popUlation
of unknown age were disregarded except as they
formed part of the death rate for all ages combined.
It should be noted that the rates for infants under I
year of age in this table differ from the infant mortality
rates shown in Tables 9 and 13, the latter being computed
on the number of live births reported for the year
rather than on the popUlation under 1 year of age at the
middle of the year.
30 See Handbook ot Vital Statistics l'.1ethods, op. cit., p. 5·3.
30
Also, the rates shown here for all ages combined differ
in a number of cases from those shown elsewhere, the
reason being that these are based on the population for
which an appropriate age distribution was available,
while the rates in Tables 8 and 14 may utilize a different
total figure. The population by age and sex might refer
to a census date within the year rather than to the midpoint,
or it might be more or less inclusive as regards
ethnic groups, armed forces, and so forth. In a few instances,
the difference is attributable to the fact that the
rates in this table were computed on the mean population
(obtained by averaging age data for two successsive Decembers),
whereas the corresponding rates in Table 8
were computed on an estimate for I July. Differences of
these types are insignificant but, for convenience, they
are noted in the table.
limitations: This rate table is based on the absolute frequencies
from Table 10 and is therefore subject to all the
limitations mentioned in connexion with that table.
The problem of obtaining precise correspondence between
deaths and population, as regards the inclusion or
exclusion of armed forces, refugees, displaced persons, and
other special groups, is particularly difficult where agespecific
death rates are concerned. In cases where it was
not possible to achieve strict correspondence, the differences
in coverage are noted. Male rates in the age range
20 to 40 years are especially affected by this non-correspondence
and care should be exercised in using these
rates for comparative purposes.
It should be added that even when deaths and population
do "correspond", the comparability of the rates may
be affected by abnormal conditions such as absence from
the area of large numbers of young men in the military
forces. Death rates may appear high in the younger
ages, simply because a large section of the able-bodied
members of the age group, whose death rates under normal
conditions might be less than the average for persons
of their age, is not included.
Table 12
Table 12 presents the number of infant deaths by age
for each sex, each year 1948-1956. This is the first Year·
book since the 1951 issue to include these statistics. The
previous presentation covered in general data for the
years 1936-1949. Table 12 is designed to provide continuity
with that table, making available data for a 21-year
span.
This table is in effect a more detailed extension of
Table 10, where deaths by age and sex through the entire
age span were presented. The more detailed treatment of
infant deaths is useful in the analysis of mortality because
the probability of dying changes markedly during the
first year of life, being considerably higher at the beginning
of the year and usually decreasing rapidly thereafter.
However, it may be noted that this pattern is not uni·
versal. In countries where environmental facilities are
not highly developed, mortality tends to remain high
through the first and subsequent childhood years.
In Table 12, infant age is classified into 5 sub-divisions
of the first year of life, as follows: under I day, 1 dayunder
1 week, 1 week - under I month, 1-5 months, and
6-11 months. An "unknown" category is not included;
frequencies reported as "unknown infant age" are in-