CHICAGO (CBS) — The City of Chicago spent $67.6 million on police overtime between the end of January and the end of August this year.

The figure this year is less than the $80.6 million police spent on overtime in the same period last year, and almost half the number spent in 2017 – when police overtime spending amounted to $110.4 million.

Still, Mayor Lori Lightfoot said on Monday that she was “angry and frustrated” that the CPD has not been able to get its overtime under control. Part of the issue is that the number of officers has increased dramatically since 2017 – when the city Office of the Inspector General said the city needed to reduce overtime in the interest of budget solvency.

That audit found that from 2011 to 2016, actual overtime spending by the Chicago Police Department increased from $42.2 million to $146 million. The CPD exceeded its annual budget for overtime in each of those years, and in 2016, CPD overtime exceeded its budget by $66.4 million, the audit said.

But in 2016, which was the most recent year in which data were available in the Inspector General’s report, there were 11,973 sworn police personnel. There are now 13,350.

Overall, since 2014, the city has spent more than $716 million on police overtime alone.