Today, sex-selective abortions are unfortunately common in countries like India and China. The introduction of ultrasound machines throughout China in the 1990s led to a sex ratio of up to 120:100 at birth due to familial and cultural pressure to have one's only child as a male. Shortly after these facts became known, it became illegal for expectant couples to know the gender of their fetus. Now, the sex ratio at birth in China has been reduced to 111:100.


The world's current sex ratio is somewhat on the high side – 107:100.


 


Extreme Sex Ratios


The countries that have the highest proportion of males to females are...


Armenia – 115:100
Azerbaijan – 114:100
Georgia – 113:100
India – 112:100
China – 111:100
Albania – 110:100


The United Kingdom and United States have a sex ratio of 105:100 while Canada has a sex ratio of 106:100.


The countries with the lowest proportion of males to females are...


Grenada and Liechtenstein – 100:100
Malawi and Barbados – 101:100


 


Adult Sex Ratio


The sex ratio among adults (ages 15-64) can be highly variable and is based on migration and death rates (especially due to war). Into late adulthood and old age, the sex ratio is often highly skewed toward females.


Some countries with very high proportions of males to females include...


United Arab Emirates – 274:100
Qatar – 218:100
Kuwait – 178:100
Oman – 140:100
Bahrain – 136:100
Saudi Arabia – 130:100


source:


http://geography.about.com/od/populationgeography/a/sexratio.htm