CONCORD, N.H. — New Hampshire’s overall high school graduation far exceeds the national average, but it ranks in the middle when it comes to low-income students, according to a new report.

The report being released Monday was compiled by multiple organizations, including former Secretary of State Colin Powell’s America’s Promise Alliance. It found that the national graduation rate based on 2012 figures has reached a record 80 percent, with Iowa topping the list and Nevada at the bottom.

New Hampshire’s rate, 86 percent, was the eighth highest, but the report also points out a significant gap between students from low-income families and those from wealthier families. The report defines low-income as those who are eligible for the federal free or reduced lunch program.

Compared to other states, New Hampshire’s low-income student population is small – 27 percent compared to 45 percent nationally. But its graduation rate for those students – 72 percent – was similar to the national rate, and far lower than then 91 percent rate for higher-income students.

New Hampshire’s overall graduation rate has risen and its dropout rate has plummeted since the Legislature raised the dropout age from 16 to 18 in 2007. That forced schools to find innovative ways to help students who otherwise would have left school, said state Rep. Anne Grassie, vice chairwoman of the House Education Committee and a former longtime member of the Rochester School Board.

The national report doesn’t drill down to individual communities or schools, but according to state Department of Education data, 47 percent of Rochester’s high school students were low-income during the 2011-12 school year, and their graduation rate was 62 percent, compared to 76 percent overall.

Grassie described numerous initiatives aimed at improving those numbers, including programs that allow students who fail classes to begin making them up online or after school instead of waiting for summer school. There’s an alternative high school, the Bud Carlson Academy, that provides at-risk students with individualized attention, and school officials make an effort to identify struggling students as soon as possible after they begin high school.

“And we pay more attention to just making sure there’s an adult to connect with every child so they know someone’s there for them,” she said. “I think those kinds of initiatives have a lot to do with kids staying in school, but it’s a combination of things. It’s not really one thing.”

The numbers are similar in Manchester, the state’s largest city, where 42 percent of students are low income. Their graduate rate from the three public high schools was 57 percent, compared to 74 percent overall.

The gap was smaller at other communities with large percentages of low-income students, however. While 42 percent of the students at White Mountains Regional High School in Whitefield are low-income, their graduation rate is 90 percent, compared to 95 percent overall. The entire graduating class, however, was only 96 students.