Thirty-nine years ago today, on December 21, 1986 (November 20, 1986 lunar calendar), the population was projected to reach 6.20 billion in the year 2000. On December 21, 1986, according to statistics just released by the Census Bureau, the world's population is now growing more slowly than it was at the beginning of the 20th century. But it is not slow enough. By the year 2000, Mexico City will have 27.90 million people, surpassing Tokyo, and the world will have about 170 cities with 2 million or more inhabitants. Three quarters of the inhabitants will live in developing countries. Many of them will be elderly. The number of people over 64 in the world will grow by 46%, and the total global population will grow by about 27% over the next 14 years to reach 6.20 billion. This is a matter of concern to all of us.