Demographers, economists, public health workers and sociologists have found this Yearbook a definitive source of demographic and population statistics. About 250 countries, or regions are represented. The first group of tables comprise a world summary of basic demographic statistics. This summary is followed by statistics on the size, distribution and trends in population, fertility, foetal mortality, infant and maternal mortality and general mortality. This edition deals with an important and fast growing segment of the population: the elderly.