1957 - United Nations Statistics Division

area. This index has been computed for every geographic
unit for which the two components were available. Where
two area figures may be available-for example, one administrative
and one inhabitable land-the inhabitable
area is the base for the computation.
Limitations: The population data given in this table are
subject to the limitations of population statistics in general,
namely variations in definitions and tabulation
methods, deficiencies in completeness of the basic count,
and differences in the method of constructing estimatesall
of which were discussed above on p. 15. To assist in the
assessing of comparability, the degree of underenumeration
in the population census has been given in Table I
when known, and the reliability of the estimates may be
ascertained by reference to the "type-of-estimate" code.
For guidance in interpreting the terms de facto and de
jure in relation to data in this table, reference may be
made to Table L, p. 20, of the 1956 Demographic Yearbook.
Per cent rates of growth are subject to all the qualifications
of the basic population figures mentioned above.
In many cases, they admittedly reflect simply the rate
calculated or assumed in constructing the estimates themselves
in the absence of adequate measures of natural and
migratory increase.I 2 Moreover, for small populations an
error up to +- 0.5 may be introduced by chance alone.
The 3-year period is also of short duration for long-range
conclusions. Nevertheless, being able to be calculated for
every area, they do provide a useful index which-with
proper cautions-can be useful also in evaluating vital
and migration statistics.
Comparability of area figures is limited by all factors
set forth on p. 15 above. Major differences between the
area figures in this volume and those shown in the corresponding
table of previous issues of the Yearbook are
usually the result of re-measurement and improved estimates,
though in a few cases, actual changes in land surface
have been effected through land recovery and construction.
Other minor differences may be due to the fact
that conversion from square miles to square kilometres,
in this volume, has been standardized on 1 square mile =
2.589998 square kilometres.
Finally, it should be emphasized that density values are
only rough indices, inasmuch as they do not take account
of the dispersion or concentration of population within
areas.
Table 2
This table presents comparable estimates of world
population by continental divisions and regions each 10
years 1920 to 1950 and in 1956, together with the annual
per cent rate of population growth between 1950 and
1956, the 1956 area in square kilometres and the number
of persons per square kilometre (density). An indication
of the reliability of the population estimates in terms of
possible percentage errors, is provided with reference to
figures for 1956; it can be presumed that estimates for
earlier years are, in most instances, subject to a similar
range of possible errors.
The estimates in this table include, wherever possible,
an adjustment for under- or over-enumeration at the various
censuses, over-estimation, categories of population
12 See 1956 Demographic Yearbook, p. 13.
20
not regularly included in the official figures, and approximations
for those countries which have not yet provided
official 1956 data. Because of this adjustment, regional and
continental sub-totals do not necessarily coincide with
those which would result from summing the component
parts in Table 1 although, in each case, the sub-totals
from Table 1 fall within the range of possible error
shown here. Because of rounding, the regional and world
totals are not in all cases the sum of their parts.
It will be noted that the estimates for 1950 shown here
for the world and for several regions-notably Northern
Africa, Tropical and Southern Africa, South East Asia,
and East Asia-differ markedly from those shown in Table
2 of the 1956 Demographic Yearbook. These revisions
have resulted from a change in the method of estimating.
Per cent rates of growth have been calculated by the
method explained in connexion with Table I, except that
the time period (t) here relates to the period 1950-1956,
rather than to 1953-1956.
The regional, continental, and world area totals were
obtained by summing the figures for individual geographic
units shown in Table I; they, therefore. include
inland waters but exclude polar regions and a few uninhabited
islands. In interpreting the population densities,
note should be taken of the fact that most of the
regions include large areas of land that are only barely
habitable and density values such as those shown make
no allowance either for the uninhabitable land or for dispersion
or concentration of population within these areas.
Coverage: The regions, which have been designed to meet
the needs of demographic statistics, have been delineated
in terms of present de facto boundaries and all retrospective
figures, having been adjusted for boundary
changes, refer to constant areas. The 14 regions for
which data are shown are constituted as follows; the basic
reference is Table 1.
(1) Northern Africa: Algeria, British Somaliland,
Egypt, Ethiopia and Eritrea (Fed. of), French Somaliland,
Italian Somaliland, Libya, Morocco, Spanish Possessions
in North Africa, Spanish West Africa, Sudan, Tunisia.
(2) Tropical and Southern Africa: the remainder of
Africa not included in (I).
(3) Northern America: Alaska, Bermuda, Canada,
Greenland, St. Pierre and Miquelon, United States.
(4) Middle America: British Honduras, Canal Zone,
Costa Rica, Cuba, Dominican Republic, El Salvador,
Guatemala, Haiti, Honduras, Mexico, Nicaragua, Panama,
and the islands of the Caribbean.
(5) South America: the entire continent.
(6) South West Asia: Aden, Bahrain, Cyprus, Gaza
Strip, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Muscat
and Oman, Qatar, Saudi Arabia, Syria, Trucial Oman,
Turkey, Yemen.
(7) South Central Asia: Afghanistan, Bhutan, Ceylon,
India, Maldive Islands, Nepal, Pakistan, Portuguese India.
(8) South East Asia: Brunei, Burma, Cambodia, Indonesia,
Laos, Malaya (Fed. of), North Borneo, Philippines,
Portuguese Timor, Sarawak, Singapore, Thailand, Viet­
Nam, West New Guinea.
(9) East Asia: Bonin Islands, China, Hong Kong,
Japan, Korea, Macau, Mongolian People's Republic,
Ryukyu Islands.