CHICAGO (CBS) — The head of the Chicago Public School system will be doing a little chest-thumping today about the high school graduation rate.

CPS Chief Executive Officer Barbara Byrd-Bennett will formally announce this afternoon that the five-year high school graduation rate – based on how many freshmen graduate within five years – is on track to hit 63 percent this year.

The district initially said Tuesday morning that it was the highest graduation rate ever, but later said it was the highest since 1999, surpassing last year’s high-water mark of 60.6 percent since the district began using the current formula for tracking graduation rates.

The 2013 graduation rate marks a 19 percentage point rise from 10 years ago.

“This graduation rate is a testament to our hard-working students, educators and administrators, but we know there is more to do,” Byrd-Bennett said in a written statement this morning.

She also said student attendance rose to 92.9 percent this year, up from 92.5 percent last year, and 91.7 percent in 2011.

CPS said that means 4,000 more students have been attending school regularly over the past two years.