By Lyndsey Layton, for The Washington Post:
The percentage of students at public high schools who graduate on time has reached its highest level in nearly 40 years, according to the most recent federal government estimates released Tuesday.
Based on data collected from the states for the Class of 2010, the National Center for Education Statistics estimated that 78 percent of students across the country earned a diploma within four years of starting high school. The graduation rate was last at that level in 1974, officials said.
