The following websites provide various statistical data about Pacific islands.
Here are additional sources that contain statistical information about religion. Some are freely available while others are licensed resources.
Comprehensive summary of statistics on the social, political, and economic conditions of the United States, from 2013 to the present. Volumes covering 1879-2012 are on the US Census site.
When working with statistics, aggregate data, and microdata, it is important to consider a number of factors:
The UCLA Data Archive's Tutorials provides excellent information about working with social science data, citing data sources, how to read codebooks, etc.
Visit the ATS Statistical Computing website for tutorials, online statistical publications, consulting, etc.