The majority of states are reporting improvement in their graduation rates for students with disabilities.

Preliminary data released this week by the U.S. Department of Education indicates that graduation rates for children with disabilities increased in 34 states for the 2013-2014 school year.

At the same time, most states also saw their overall graduation rates rise, the agency said.

“The hard work of America’s educators, families, communities and students is paying off, particularly after several years of intense work by educators transitioning to new, higher standards,” said U.S. Secretary of Education Arne Duncan.

Traditionally, students with disabilities have struggled to graduate high school in the same numbers as typically-developing kids. As of the 2012-2013 school year, the national graduation rate for those with disabilities was nearly 62 percent compared to 81 percent for all students, a record high.

Though the latest data will not be final for several more months, the Education Department said initial figures for the 2013-2014 school year suggest the disparity may be easing. The differential in graduation rates for students with and without disabilities remained steady in 12 states and declined in 21 states.

The figures released this week include graduation rates for Washington, D.C. and every state except Idaho, with breakdowns for some subgroups of students by race, disability status and other variables. The data is considered provisional and states can continue to submit updates before it is finalized, so no national graduation rates have been calculated yet.

Graduation rates reported for students with disabilities varied tremendously by state, with a low of less than 28 percent in Nevada and a high of 83 percent in Arkansas. The variation is due in part to reporting differences by state, the Education Department said.

Federal data on graduation rates accounts for the number of students who obtain a high school diploma within four years.