In the year 2000, there were 76.6 million students 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 greater than $51,000, exceeding the national average of those without a high school diploma by more than $23,000, according to a 2005 study by the U.S. Census Bureau. The 2010 unemployment rate for high school graduates was 10.8%; the rate for college graduates was 4.9%.
The country has a reading literacy rate at 99% of the population over age 15, while ranking below average in science and mathematics understanding compared to other developed countries. In 2008, there was a 77% graduation rate from high school, below that of most developed countries.
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. A 2000s study by Jon Miller of Michigan State University concluded that "A slightly higher proportion of American adults qualify as scientifically literate than European or Japanese adults".
 School grades
Most children enter the public education system around ages five or six. The American school year traditionally begins in August or September, after the traditional summer recess. Children are assigned into year groups known as grades, beginning with preschool, following by kindergarten and...