The birthrate dropped by a big margin from 33.43 per thousand in 1970 to 21.06 per thousand in 1990,and the natural population growth dropped from 25.83 per thousand to 14.39 per thousand.

• 中国人口出生率、人口自然增长率、妇女总和生育率都大幅度下降。1990年与1970年相比，出生率由33.；43‰下降到21