Warfare that was endemic to the Balkan Peninsula throughout much of its early history, exploitation by the Ottomans, and living conditions that contributed to a short life expectancy served to hold down the population of the area before independence. Since 1878, although the country has participated in four wars and most migratory movements have been at Bulgaria's expense, the population has tripled.

Growth has been comparatively steady during the century of independence. Its rate has fluctuated but not widely. Until 1910 it was high. It dropped during the 1910-20 decade, which included the Balkan wars and World War I. The period of greatest growth occurred between the great wars, and the three decades since 1941 have been the periods of least growth.

Vital statistics supplied by the Bulgarian government to the United Nations in 1972 indicated an annual growth rate of 0.7 percent. This was based on 16.3 births per each 1,000 of the population, as against 9.1 deaths. Infant mortality, included in the overall death rate, was 27.3 deaths during the first year for each 1,000 live births. In early 1973 the government was alarmed at an apparent change in the statistical trend. Complete information for 1971 showed that, instead of 16.3 births per 1,000, the actual figure was 15.9. Indications were that in 1972 it was dropping to 15.4.

Internal migrations since 1878 have consisted largely of the initial movement of the rural population from the hills to the plains and the later movement of people from the rural areas to the towns. External migrations have been more complex. The earliest occurred in the aftermath of the liberation; later ones have resulted from the animosities and territorial changes associated with the various wars in which the country has been involved.

Having occupied the territory, Turks left in wholesale numbers when they lost control of it. More of them departed during the Balkan wars. Large groups emigrated in the 1920s and 1930s, and more were forced to leave after World War II. Estimates as to the numbers involved in each move vary widely; the two largest after 1880 were those in the 1920s and after World War II, and the total in all emigrations of Turks probably equals or exceeds the 700,000 that remain in the country. Natural population increases have been such that, over the long term, the actual number of Turks in the country has changed relatively little.

There have been smaller population exchanges with each of the other neighbors. In the mid-1920s about 250,000 Bulgarians moved from Greek Thrace into Bulgaria, and about 40,000 Greeks left Bulgaria for Greece. After 1940, when southern Dobrudzha was annexed from Romania, some 110,000 Romanians were exchanged for about 62,000 Bulgarians. Macedonians, also in considerable numbers, have chosen between Bulgaria and Yugoslavia, requiring many of them to move.

The Jewish people, faring much better in Bulgaria during World War II than they did in Adolph Hitler's Germany or in most of the countries overrun by the Germans, have nonetheless emigrated to Israel in large numbers. Before that war there were about 50,000 of them in the country, but 90 percent or more of them emigrated during the early postwar years.

All of the major emigrations were completed before 1960. There appear to be no reasons why others of similar proportions should occur in the foreseeable future.

Working Force

In mid-1972 there were 5.8 million people in the working-age group (fifteen to sixty-four years), although the legal retirement age in most employment situations is sixty or sixty-five for males and five years younger for females. About 4.4 million—just over one-half of the total population and three-quarters of those of working age—constituted the labor force. Population projections indicate that in the ten-year period after 1972 the working-age group will increase by 0.3 million, but a large percentage of the increase will be in the segment of the group aged fifty to sixty-four.