据联合国1980年的预测报道,1980年世界人口为44亿,其中发达国家为11亿,发展中国家为33亿。到2000年世界人口将增加到61亿。发达国家为13亿,增长18.2%,发展中国家为48亿,增长45.5%。随着人口出生率的下降和寿命的增长,人口的年龄构成也将发生变化,发展中国家和发达国家人口构成的差异将 According to the report of the United Nations in 1980, the world population was 4.4 billion in 1980, of which 1.1 billion were in developed countries and 3.3 billion in developing countries. By the year 2000, the world population will increase to 6.1 billion. The number of developed countries was 1.3 billion, an increase of 18.2%, and that of developing countries was 4.8 billion, an increase of 45.5%. As the birth rate falls and life expectancy increases, the age composition of the population will also change, and the differences in population composition between developing and developed countries will increase.