Who will graduate high school? Major disparities in Connecticut’s schools.

For an idea of the achievement gap Connecticut students face, one needs to look no further than the graduation rates of the state’s different student populations.

With 83 percent of Connecticut students graduating on time in four years, the state is tied for 12th place among the 50 states, according to new preliminary data released Monday by the U.S. Department of Education.

The state comes in eighth place for the white students that graduate on time, compared to 26th place for black students and 38th for Hispanic students. The state comes in 41st place for graduating students from low-income families, 24th for special education students and 28th for those students who enter school with limited English proficiency.

The completion rates for those who should have graduated 2011 were the worst in Connecticut for students with either special education needs, from a low income family or for those with limited English proficiency when they entered school. All three groups saw just six out of every 10 students graduate on time.

This is the first time a national comparison of graduation rates has been possible, as their was no national standard for measuring such data.

When Connecticut switched over to this new comparison standard last year, the state’s graduation rates that are reported by the State Department of Education dropped by more than 10 percent from the previous year.

Curious what the graduation rate is in your district? Here’s the breakdown by district and subgroup last year. Norwich had the worst graduation rate with just 29 percent of its students graduating on time. Bridgeport and New Britain were next in line with, with 55 percent overall completion rates.

The state department is expected to release completion results for those that should have graduated this past sping in the near future.