This is primarily due to declining fertility in parts of the developing world as a result of improved economic and social conditions, and reproductive health efforts. Unfortunately, it is also due partly to increasing numbers of deaths from hunger, AIDS and other infectious diseases, and casualties in regional and local conflicts. Despite this decline, however, world population is currently growing by about 80 to 85 million people each year. This is roughly the equivalent of adding another Germany every year, another Spain every six months, or another San Francisco every 80 hours. This growth is a result of natural increase, declining mortality, and increased longevity.
Natural increase is defined as a surplus of births over deaths in a given period.
According to the Population Reference Bureau's 1999 World Population Data Sheet, world birth rates currently average 23 per 1,000 population, and world death rates average 9 per 1,000 each year. Birth rates vary by region from a high of 46 per 1,000 in Middle Africa to a low of 9 per 1,000 in Eastern Europe. This is a very positive trend, and an important indicator of improving global health. But it also contributes to population increase in the short term. It ranges from 150 deaths per 1,000 births in Western Sahara and Afghanistan, to a low of 3.6 deaths per 1,000 in Sweden and 3.7 in Japan.