http://www.migrationpolicy.org/pubs/NCIIP_English_Instruction073107.pdf
McHugh, M, Gelatt, J, Fix, M (7/2007). Adult English instruction in the United States: Determining need and investing wisely. Migration Policy Institute.
From the article: “In this report, we provide census-based estimates on the number, educational attainment, and English skills of adults who are lawful permanent residents (LPRs) or unauthorized immigrants. The report translates these numbers into estimates of the hours of instruction these immigrants will need to achieve the English skills necessary for civic integration or what some refer to as “patrioticassimilation” into US society, and, in the case of youth age 17 to 24, the English skills necessary forpostsecondary study. The report includes both national- and state-level estimates of instructional needs and the costs associated with meeting them.”