E. PERCENT AGE DISTRIBUTION OF ENUMERATED Birth and death rates over a period of time largely determine the age composition of the population. Based on data for the most recent year since 1950 the proportion of the population in the productive ages as well as in the older age group is greatest in the more industrially advanced countries of the West. In other parts of the world, comparatively high proportions of the population are children. In those countries which have a higher proportion of older persons, the degenerative diseases are likely to contribute most to the overall death rate. With many of the infectious diseases which formerly caused so many deaths virtually brought under control in these countries, more people survive childhood and early adulthood, later to become victims of heart disease, cancer, and other degenerative diseases. In contrast, the less-developed countries which have the highest proportion of children also are those which have the greatest incidence of infectious diseases. PART 2. HEALTH INDICES A. ANNUAL CRUDE BIRTH AND DEATH RATES BY REGIONS About 90 million births and approximately 49 million deaths are estimated to occur annually in the world population. The differ ence between the births and the deaths along with the amount of migration determines the rate of population growth in any given region. With the exception of Oceania, migration has played a relatively small part in population growths. In Oceania, it is estimated that almost a third of the population increase is accounted for by net immigration into the two major countries of that area, Australia and New Zealand. The data set forth in the accompanying chart are those which wer available for the most recent year since 1952. |