TORONTO - Five years after Ontario eliminated Grade 13, only 69 per cent of students completed the four-year high school program in four years.

The Education Ministry reported a 77 per cent graduation rate for Ontario high schools last month, but that included students who go back for a fifth year.

Education Minister Kathleen Wynne said both graduation rates are good news because they show more students are completing high school.

"In fact the four-year grad rate is even a better story than the five-year grad rate, so the gap is closing," she said.

"It's obvious that the supports that we're putting in place are working."

Despite the number of students returning for a fifth year, eliminating Grade 13 was the right thing to do, Wynne said, especially when Ontario was the last jurisdiction in North America with the extra year of high school.

"I don't think it's a mistake, but I also don't think we need to worry about kids who want to come back and do some extra courses," she said.

There are lots of reasons students go back for a fifth year, Wynne added.

"They may go back because emotionally they're not ready," she said. "They may go back because there's some courses they wanted to take that they didn't have a chance to.

"It's all a good story in terms of kids getting the courses that they want and getting onto the post-secondary or skilled trade that they want to do."

The 69 per cent of students who graduated in 2008 after four years was up from 56 per cent in 2003-04, representing an increase of almost 20,000 students who completed high school in four years.

The 77 per cent of students who received their diploma after five years of high school was up substantially from 68 per cent in 2003-04.

About 115,000 students graduated from Ontario high schools last year.

The government had been reluctant to publish the four-year graduation rate until pushed by the media.

American states are not allowed to include students who take more than four years to complete high school in their graduation rates unless the students are developmentally disabled or still learning English.

Other provinces use different ways to calculate graduation rates and some, including Alberta, P.E.I. and Newfoundland and Labrador, consider high school to start at Grade 10 instead of Grade 9.

Manitoba and Nova Scotia have similar programs to Ontario, and both measure students who complete high school in four years. Manitoba's most recent grad rate was 79 per cent, while Nova Scotia's was 85 per cent.