Sex ratio

Ratio between the number of males and the number of females, expressed as the number of males per 100 females.

At birth, the sex ratio is 105 boys for 100 girls. Since male mortality is generally higher than female mortality, the sex ratio decreases with age, and the proportion of women overtakes that of men. In France, there are more women than men from age 35 (in 2005) and eight in every ten centenarians are women.