In countries such as the U.S. and France, where it is not permitted to take official statistics on religious affiliation as part of the national census, demographic data for Muslims must be gleaned from other sources. One way of obtaining estimates is through surveys and immigration data focused on whether an individual has immigrated from, or has roots in, a predominantly Muslim nation, culture, or ethnic group.

The data above illustrates both the diversity in Muslim cultures worldwide and within Muslim minority populations in the West. France�s colonial history has engendered a French Muslim population with origins in the Maghreb, usually defined as encompassing Morocco, Algeria, Tunisia, and sometimes Libya. In contrast, only one-quarter of American Muslims are Arab (including North Africa), while a third are South Asian, and another third are African-American. Both populations are noteworthy in their low numbers of Muslims tracing their roots to South East Asian countries such as Indonesia, the world�s most populous Muslim nation, and Malaysia.