RICHMOND—The 2011 on-time graduation rate at two out of three Western Tidewater public high schools was lower than the state rate, which increased by 1 percentage point to 86.6 percent.

At the same time, Windsor High School saw its student dropout rate increase by 1 percentage point to 8.1 percent of its students, and Southampton and Franklin high schools both saw theirs fall by 7.2 percentage points to 7.8 percent and 9.7 percent, respectively. The statewide average for 2011 was 7.2 percent.

The Virginia Department of Education on Tuesday released its report for 2011 on-time graduation rates. These are students who were first-time ninth graders during the 2007-2008 school year and earned a Board of Education-approved diploma within four years. On-time graduation has increased by 4.5 points since 2008, the first year VDOE reported graduation rates for the state, school districts and high schools.

Windsor’s on-time graduation rate for 2011 was 87.9 percent, down from 90.8 percent one year earlier. Windsor’s rate was above the state average and higher than Franklin’s 84.5 percent and Southampton High School’s 86.1 percent for 2011.

Franklin’s on-time graduation rate improved from 79.8 percent in 2010 and its dropout rate improved from 16.9 percent in 2010 to 9.7 percent in 2011. And at Southampton, the graduation rate improved from 80.4 in 2010 and its dropout rate fell from 15 percent in 2010 to 7.8 percent in 2011.

“We’ve worked very hard for it,” said Southampton High School Principal Allene Atkinson. “We anticipate success. Our whole goal has been to try to help our kids and give them a chance to be successful.”

The effort involved students, parents and teachers, she said.

“We had an incredible effort from the staff, and the students have been extremely determined and the parents,” Atkinson added. “Everyone has worked together.”

No one from Franklin or Windsor schools returned phone calls.

The graduation rates of black students increased 1.4 points to 80.3 percent in the state. At Southampton, 82.9 percent of black students graduated on time in 2011 compared to 80.2 percent one year earlier. Windsor graduated 90.9 percent in 2011 and 93.5 percent in 2010. At Franklin, 81 percent graduated on time in 2011 and 80.2 percent one year earlier.

The graduation rate for white students at Southampton was 81.1 in 2010 and 89.5 in 2011, Franklin was 78.9 percent in 2010 and 100 percent in 2011, and Windsor was 90.4 percent in 2010 and 87 percent in 2011.