Education in the United States is provided mainly by government, with control and funding coming from three levels: federal, state, and local. At the elementary and high school levels, curricula, funding, teaching, and other policies are set through locally elected school boards with jurisdiction over school districts. School districts are usually separate from other local jurisdictions, with independent officials and budgets. Educational standards and standardized testing decisions are usually made by state governments.
Children are required to attend school until the age of 16-18 depending on the state. Many more states now require children to attend school until the age of 18. Some states have exemptions for those 14-18. Students may attend public schools, private schools, or homeschool. In most public and private schools, education is divided into three levels: elementary school, junior high school (also often called middle school), and senior high school. Grade levels in each vary from area to area.
76.6 million students were enrolled in schools from kindergarten through graduate schools. Of these, 72 percent aged 12 to 17 were judged academically "on track" for their age (enrolled in school at or above grade level). Of those enrolled in compulsory education, 5.2 million (10.4 percent) were attending private schools. Among the country's adult population, over 85 percent have completed high school and 27 percent have received a bachelor's degree or higher. The average salary for college or university graduates is $45,400, exceeding the national average by more than $10,000, according to a 2002 study by the U.S. Census Bureau.
The country has a reading literacy rate at 98% of the population over age 15, while ranking below average in science and mathematics understanding. The poor performance has pushed public and private efforts such as the No Child Left Behind Act. In addition, the ratio of college-educated adults entering the workforce to general population (33%) is slightly below the mean of other developed countries (35%) and rate of participation of the labor force in continuing education is high. However, a recent study showed that "A slightly higher proportion of American adults qualify as scientifically literate than European or Japanese adults".