WASHINGTON — The national high school graduation rate hit a record high in 2013-2014, with 82 percent of students earning a diploma on time, according to federal data released Tuesday morning.
The numbers show that every category of student — categorized by race, income, learning disabilities and whether they are English language learners — has posted annual progress in graduation rates since 2010, when states adopted a uniform method of calculating those rates.
''America's students have achieved another record milestone by improving graduation rates for a fourth year,'' said Education Secretary Arne Duncan. ''The hard work of teachers, administrators, students and their families has made these gains possible and as a result many more students will have a better chance of going to college, getting a good job, owning their own home, and supporting a family. We can take pride as a nation in knowing that we're seeing promising gains, including for students of color.''
The gap between graduation rates for white students and black and Hispanic students has narrowed, but disparities persist.
In 2013-2014, 87.2 percent of white students graduated on time, while the rate for blacks was 72.5 percent and Hispanics was 76.3 percent.
The data, collected by the National Center for Education Statistics, estimate the graduation rate by dividing the number of high school graduates in a class by the number of students who entered that class as freshmen four years earlier, with some adjustments made for transfers.
The state with the highest graduation rate was Iowa, where 90.5 percent of the Class of 2014 graduated on time. The District of Columbia posted the lowest rate when compared to states.
High school graduation rates are one measure of school success, but experts caution about placing too much value on them because graduation requirements are set locally and can change over time, making comparisons across jurisdictions difficult.
Official statistics had long overstated the nation's high school graduation rates, with the Education Department putting the average above 80 percent and some states reporting rates above 90 percent. States used dozens of different reporting methods, with some figuring into their rates high school dropouts who later earned the equivalency certificate known as a General Educational Development diploma, or GED.
All 50 states agreed to adopt the same method of calculating those rates in 2010, to promote some better accountability and transparency.
''A high school diploma is absolutely critical, absolutely attainable and key to future success in college, in the workforce and in life,'' Duncan said. ''It is encouraging to see our graduation rate on the rise and I applaud the hard work we know it takes to see this increase. But too many students never get their diploma, never walk across the graduation stage and while our dropout numbers are also decreasing, we remain committed to urgently closing the gaps that still exist in too many schools and in too many communities.''