CHICAGO (CBS) — Chicago Public Schools officials have lowered the district’s graduation rates for four years, after revealing they had been inflated, calling the administration’s accounting procedures into question.

The 69.4 percent graduation rate originally reported by CPS for the 2013-14 school year – which Mayor Rahm Emanuel had called a record high for the district – was lowered to 66.3 percent. The three previous years’ graduation rates also were dropped an average of more than 2 points each year.

READ MORE: Police Respond To Shots Fired Call At Clark And Lake CTA Stop

Some called the change in graduation rates a minor modification, but others questioned the timing and politics of Thursday night’s announcement, given how often the mayor praised rising CPS graduation rates during his successful run for re-election.

According to the Chicago Tribune, the district’s previously stated graduation rates were questioned as early as January in a report by the district’s inspector general, but CPS did not announce the revisions until Thursday, nearly six months after he won re-election.

READ MORE: Man Found Shot Dead Under Viaduct In Stony Island Park

In the past, the district counted those leaving school for a GED program, alternative schools outside CPS, or job training programs as “transfers” who counted toward the graduation rate, rather than as “dropouts.”

CPS said it is now accurately counting transfers and dropouts.

MORE NEWS: Four In Custody Following Domestic Incident 'Involving A Firearm' At Sky Zone In Orland Park

Despite the lowering of graduation rates, an Emanuel spokeswoman emphasized the rates are still moving in the right direction overall.