In Baltimore in recent years:

Zero students at 23 public schools were math proficient.

At some high schools, the average GPA was less than 0.13.

77% of high school students read at grade school or kindergarten level.

Baltimore spends $23,137 per student.

This might have something to do with it: An average IQ of 76 for black students in the city of Baltimore (just 6 points above the former classification threshold for "mentally retarded" / borderline intellectual functioning).

The white average (86) is exceptionally low, as well.