B. WORLD POPULATION

In 1957, the world population was estimated to be about 2,790 million persons.

Over one-half of this number (55.8 percent) live in Asia, 15 percent in Europe, 9 percent in North and Middle America, 8 percent in Africa, 7 percent in the U.S.S.R., 4.7 percent in South America, and the remaining 0.5 percent in Oceania.

It may be noted that only 9 countries in the world have estimated populations which exceed 50 million persons:

C. DISTRIBUTION OF WORLD POPULATION

This map of the world showing continents and selected countries distorted on a scale proportionate to each 1 million of population is included to permit a more adequate appraisal of the significance of the disease distributions shown on later plates. Although this map was constructed on the basis of estimated populations for 1950, an analysis of the estimates for 1957 shows that even though populations have increased, the proportionate distribution has remained about the

same.

Such a map presents an informative picture. The 8.6 million square miles of the U.S.S.R. shrinks in comparison with the 3.7 million square miles of heavily populated China mainland and the almost equally densely populated 1.2 million square miles of India. Brazil, with only one-third of the actual land area of South America, appears to occupy most of that continent, while Canada with a total land area third largest in the world (after U.S.S.R. and China mainland) becomes only a narrow strip resting on top of the United States.

According to "World Population and Production," by the Wotinskys, population density is greatest along the China mainland coast, extending north to Korea and Japan and south to the Philippine Islands and Indonesia. Here, with approximately 620 million persons living on less than 1.5 million square miles, there is an average of about 430 persons per square mile. Nearly as crowded are the 400 million people concentrated in a million square miles in the valley of the Ganges, south India, and Ceylon-an average of 410 per square mile. Europe (including European U.S.S.R.) has an aggregate of 370 million people in an area of 1.2 million square miles. The fourth largest concentration is the populous northeast section of the United States with 90 million persons in 500,000 square miles. Other concentrations of population are found along the Pacific coast of North America, the Atlantic coast of South America, in the Caribbean Islands, and in Africa at the mouth of the Niger River and in the Nile Valley.

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D. RATE OF GROWTH OF WORLD POPULATION BY REGION 1952-56

The world population has been growing at an accelerating rate under conditions of a relatively stable birthrate and a declining death rate. The rate of growth for the entire world is about 1.6 percent per annum, or more than 40 million persons per year.

The fastest rates of increase are occurring in Middle America (2.7 percent), southwest Asia (2.5 percent) South America (2.4 percent), and Oceania (2.4 percent). The smallest rate of change has occurred in Europe, especially Northern and Western Europe (0.6 percent). The data presented on the accompanying chart show the average percent increase per year as determined from the mean of the annual increases and the mean population over the 4-year period 1952-56.