expectancy statistics. Around the turn of the century average life
expectancy was forty years, and females are estimated to have outlived
males by less than six months. Seventy years later, average life
expectancy had increased by twenty-five years, but females were
outliving males by an average of about four years. Projected from the
1965 census and from vital statistics information accumulated since that
time, numerical equality between the sexes came about in the late 1960s,
and in mid-1973 it was estimated that females outnumbered males by the
small majority of 4.334 million to 4.333 million.

Another exceptional feature of the Bulgarian population is the unusual
number of very old people. Nearly 1 percent of the population in 1970
was eighty years old or older, and more than 500 people were
centenarians. Of these, three-fifths were women.

People in rural areas, after having long outnumbered those in cities and
towns, became the minority in 1969. More than four-fifths of the
population was rural at the time of independence in 1878, and more than
three-quarters was still rural in 1947. The movement to the towns
accelerated with the post-World War II industrialization. Towns that
attracted industries have grown by factors of five or more since 1920,
and by far the most dramatic growth has occurred since 1947.

With 8.7 million people occupying 42,800 square miles in 1972, the
average population density for the country was 203 persons per square
mile. Regions where the densities were highest include the Sofia Basin
and the southwestern portion of the Thracian Plain. The population was
more dense than average in the western and central portion of the
Danubian plateau, in the lower eastern Rodopi, and in the vicinities of
Varna and Burgas on the Black Sea coast. It was least dense in the
higher mountains, particularly in the high western Rodopi, the Pirin and
the Rila, and along the narrow high ridge of the Stara Planina.

Dynamics

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