Statistics that track whether Virginia’s high school students are graduating, and how soon, went in the negative direction for two of Suffolk’s three high schools and for the division as a whole.

While King’s Fork High School improved both rates significantly, the rates at Lakeland and Nansemond River high schools suffered.

“We’ll work with them to increase their rates,” Deputy Superintendent Jacquelyn Chavis said on Tuesday. “We’ll look at the data and get more specifics from the principals at Nansemond River and Lakeland, and we’ll work them to increase their rates, since they dropped.”

The on-time graduation rate measures the number of students who began high school four years ago and graduated in the class of 2015. The dropout rate counts those who have officially dropped out without graduating. The two rates do not add up to 100 percent, because some students could still be enrolled and trying to finish, might have moved without informing the school division, or some other situation.

The division’s on-time graduate rate fell slightly from 86.4 to 86.2. The dropout rate rose from 8.8 to 9.5.

At Lakeland, the on-time graduation rate slipped one point to 81.9. The dropout rate rose from 11.6 to 13.1.

At Nansemond River, the on-time graduation rate went down from 92.3 to 88.8. The dropout rate went from 3.6 to 6.5.

At King’s Fork, the only place where the rates improved, the on-time graduation rate rose three percentage points to 87.7. The dropout rate decreased from 10.7 to 9.

Division-wide, 43 percent of the students who first entered high school in 2011 earned an advanced diploma.

Chavis noted that while there are some factors the division cannot control, the schools are focusing on what they can control.

“There are some academic challenges that keep kids from doing well,” Chavis said.

She also said the division is working to improve how it tracks students who have left without graduating, whatever the reason.

Statewide, the on-time graduation rate now tops 90 percent, and more than half earned an advanced diploma. The statewide dropout rate is 5.2 percent.

Since 2011, high schools have had to meet an annual benchmark for graduation and completion to earn full accreditation under Virginia’s Standards of Learning accountability program. Schools receive full credit for students who earn diplomas and partial credit for students who remain enrolled, earn GEDs or otherwise complete high school.

On-time graduation has increased by 9.2 points since 2008, the first year VDOE reported accurate graduation rates based on longitudinal student data fully accounting for student mobility, retention and other factors. During this same period, the state dropout rate fell to 5.2 percent, compared with 8.7 percent in 2008.