Men make up a majority of the world population, with around 40 million more men on Earth than women. However, different factors allow women to live longer than men, reflected by a larger female population among those 65 years old or older. By the time humans are at least 65 years old, 56% of that population will be female.

But there are also factors that can change that balance from country to country and region to region, depending on issues such as migration, war, public health, and general life expectancy. That could make a location’s population dramatically imbalanced between the genders. See where these factors cause disparity between the genders, and why some countries and regions have a population that leans more male or female, according to World Population Review (as reported by Visual Capitalist).

Middle Eastern Countries Are More Male

Middle Eastern countries, led by Qatar, dominate the top countries with a gender disparity that favors men. Migration is a major factor for this difference, as these countries have been building industries such as construction, energy, and infrastructure with temporary workers from other countries. In Qatar, for example, more than 85% of the country’s population is made up of migrant workers, pushing its ratio to 243.7 men for every 100 women in the country.

Other countries in the area have lower ratios between men and women, but they also have similar issues with migration, causing a large divide between men and women within their borders.

Here are the top five countries/regions that have the highest imbalance with a population that skews more male, based on the number of men per 100 women:

Migration Also Influences Female-Dominant Countries

While male migration has influenced the population of countries and regions in the Middle East, it’s also created larger female populations in other countries. Places like Macau and Hong Kong hire women in positions such as domestic labor, pushing populations higher for women than men.

But that may not be the full story with other factors contributing to the imbalance. In Hong Kong, for example, an aging population is also contributing to the difference. Because women tend to live longer than men, older women who have lived longer than men among similar ages can skew the population. The young population makes up 10% of the population in Hong Kong while the elderly population is closer to 25% of the total population with women making up a disproportionate part of the population.

Former Soviet states also make up a large portion of countries with more women than men. In 1950, the Soviet Union only had 77 men to 100 women due to losses during World War II. While it did begin to recover by the 1990s, the population is still affected by shorter male life expectancy, war losses, and alcoholism among the male population. That has led to former Soviet states taking up seven of the top 12 spots for countries with larger female populations than male.

The top five countries/regions that have a larger female population, based on the number of men per 100 women, include:

How the United States Stacks Up

In the U.S., men outnumber women—but not by much. There are 101 men for every 100 women in the country, which is slightly below the global average of 101.2 men for every 100 women.

However, that ratio can vary dramatically from state to state. Alaska, for example, has the highest male population ratio, with 110.5 men for every 100 women. If it were a country, that ratio would place it among the top 15 countries with the highest male-to-female ratio, besting the current 15th place Greenland with 110.2 men for every 100 women. One factor is likely the male-dominated professions in Alaska, including lumber and fishing professions.

On the other side, Delaware has the highest ratio of women compared to men, with only 94.1 men for every 100 women. Mississippi and Alabama are close in rankings, with 94.2 women and 94.3 women, respectively, compared to men.