European Mexicans are Mexican citizens of European descent. Mexico does not have a racial census, but estimates from different international organizations of this ethnic group as a segment of the country's population range from 9% according to The World Factbook to as high as 10-20% (approximately one-tenth to one-fifth) according to Encyclopædia Britannica. Another group in Mexico, the "mestizos", includes people with varying amounts of European ancestry, with some having a European admixture higher than 90%. However, the criteria for defining mestizo varies from study to study, and in Mexico a large number of white people have been historically classified as mestizos because the Mexican government defines ethnicity on cultural standards as opposed to racial ones.