"This report provides information on the number and characteristics of people in the United States in 2007 who spoke a language other than English at home. While the vast majority of the population 5 years old and over in the United States spoke only English at home (80 percent), the population speaking a language other than English at home has increased steadily for the last three decades. The number of speakers increased for many non-English languages, but not all. This changing landscape of speakers of non-English languages in the United States is highlighted in this report."
American Community Survey Reports: ACS-12
Government Printing Office: http://catalog.gpo.gov/