The sex ratio in 2010 of the Korean population is 98.7, indicating that females outnumber males. The sex ratio map shows that the areas with lower ratios (i.e., the areas with more females) are often -gun districts that are losing population.
On the other hand, the high sex ratio districts appear in the areas with heavy manufacturing and chemical industries such as Ulsan, Geoje (Gyeo- ngsangnam-do), Gwangyang (Jeollanam-do), and the northern part of Chungcheongnam-do, where many development projects have taken place. The
military border regions in Gangwon-do also show high sex ratios. In the age group including the early 30s, the sex ratio is above 100 (i.e., more males), but it drops below 100 in the population older than 50. The sex ratio drops further in the elderly group. Overall, the sex ratios of -myeon districts have fallen below 100 since 1995. In the case of -dong districts, it has been below 100 since 2005. The ratios in -eup districts remain above 100.