The sex ratio is the ratio of males to females in a population. In most sexually reproducing species, the ratio tends to be 1:1. This tendency is explained by Fisher's principle. For various reasons, however, many species deviate from anything like an even sex ratio, either periodically or permanently.
Number of Men for Each 100 Women:
- India: 108
- China: 106
- Turkey: 102
- Indonesia: 100
- Brazil: 98
- UK: 98
- US: 97
- France: 96
- Russia: 85
