NORWALK - High school graduation rates are on the rise in Connecticut.

Education officials say the graduation rate for the 2011-2012 school year increased more than 2 percent from the previous year.

However, officials say there's still an achievement gap between students from low- and high-income families.

They say 66 percent of students eligible for the state's free lunch program graduated after four years compared with 93 percent of students who were not eligible.