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.

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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.

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“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.

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