birth ratio

基本解释

The normal human birth ratio is 106 males for every 100 females.
正常的人类出生比例是每106个男性对应100个女性。
But since 1970, the U.S. and Japan have experienced a downward shift in this male-to-female birth ratio, researchers report in the online edition of the journal Environmental Health Perspectives.
但据研究人员在环境健康观察期刊在线版上发表的报告显示，从1970年开始，美国和日本的男女出生比率开始下降。
The book points out that the expanding male to female birth ratio will mainly affect China's marital and family structure and employment structure, as well as the "population's ecological security."
该书指出，出生性别比攀升主要是影响婚姻家庭结构、就业结构变迁和“人口生态安全”。
english.peopledaily.com.cn

China's skewed birth ratio (118 boys to every 100 girls) means that there will be a surplus of about 24m bachelors by 2020.
ECONOMIST: Singletons are getting some help finding a mate
It shows the sex ratio at birth, whereas the census shows the ratio for children aged 0-6 (census figures for the sex ratio at birth have not been published).
ECONOMIST: Banyan
India does, in fact, publish data (since 1999) on the sex ratio at birth.
ECONOMIST: Letters