To search for statistics on an ethnic or cultural group, go to google and do a searchan example.....Mexican Americans Statistics site: gov....... This search should give you lots of statistics from the government.
For general information about where your cultural/ethnic group originated, look in some of these country guides for quick information about history, culture, family, education, etc.
CQ Researcher is a magazine that puiblishes weekly reports on issues and controversies in the United States and worldwide. The reports are lengthy and objective with background info and statistics. Some of the reports are on issues that relate to cultural diversity.