Percentage of female migrants out of total international migrant stock. International migrant stock is the number of people born in a country other than that in which they live. It also includes refugees. Limitations and exceptions: In estimating the international migrant stock, international migrants have been equated with the foreign-born population whenever this information is available, which is the case in most countries or areas. In most countries lacking data on place of birth, information on the country of citizenship of those enumerated was available, and was used as the basis for the identification of international migrants, thus effectively equating, in these cases, international migrants with foreign citizens. Equating international migrants with foreign citizens when estimating the migrant stock has important shortcomings. In countries where citizenship is conferred on the basis of jus sanguinis, people who were born in the country of residence may be included in the number of international migrants even though they may have never lived abroad. Conversely, persons who were born abroad and who naturalized in their country of residence are excluded from the stock of international migrants when using citizenship as the criterion to define international migrants. Using country of citizenship as the basis for the identification of international migrants has also an impact on the age distribution of international migrants. In countries where citizenship is conferred mainly on the basis of jus sanguinis, children born to international migrants tend to be considered foreign citizens and are thus included in the count of international migrants. Conversely, in countries where citizenship is conferred mainly on the basis of jus soli, children born to international migrants are granted citizenship upon birth and are thus excluded from the migrant stock. Statistical concept and methodology: Most of the data used to estimate the international migrant stock by country or area were obtained from population censuses. Additionally, population registers and nationally representative surveys provided information on the number and composition of international migrants. In estimating the international migrant stock, international migrants have been equated with the foreign-born population whenever this information is available, which is the case in most countries or areas. In most countries lacking data on place of birth, information on the country of citizenship of those enumerated was available, and was used as the basis for the identification of international migrants, thus effectively equating, in these cases, international migrants with foreign citizens. Among the 232 countries or areas included in the 2015 revision of International Migrant Stock, 92 per cent had at least one data source on the total migrant stock since the 2000 census round. For countries or areas with at least two data points, interpolation or extrapolation was used to estimate the migrant stock for the six reference years from 1990 to 2015. To estimate the total migrant stock for countries or areas with only one data source, the growth rates of the total migrant stock in the relevant major area or region were used, where appropriate, to estimate changes in migrant stock levels.