The U.S. Census Bureau releases the 2009 Statistical Abstract of the United States. It is the standard summary of statistics on the social, political, and economic organization of the United States. It also is designed to serve as a guide to other statistical publications and sources. Appendix I of this volume contains the Guide to Sources of Statistics, the Guide to State Statistical Abstracts, and the Guide to Foreign Statistical Abstracts. Tables reflect national data, and also data for regions, individual states, and smaller number of metropolitan areas and cities. Appendix II, Metropolitan and Micropolitan Statistical Areas: Concepts, Components, and Population, presents explanatory text, and complete current listing and population data for metropolitan areas defined as of December 2006.