In order to get a better picture of how students who qualified for special education services were served by the school system, the City Council passed a law last year requiring that the Department of Education annually report its findings. 

But there was a problem: flawed data. The Special Education Student Information System, the computer-based system that tracks special ed services, relied on manual input of some information and did not communicate with a related computer tracking system.

The result of these glitches is a less than accurate report, released for the first time on Monday.

Ideally, it should shed light on how many students were evaluated for special education services, and whether those evaluations happened in a timely fashion; whether students received mandated services listed on their Individualized Education Programs; and who qualified for special education, including family income status. 

"Our Special Education team worked to manually produce an accurate report, but due to SESIS's flaws, we simply cannot have complete confidence in some of this data," said Harry Hartfield, a Department of Education spokesman, adding that staffers painstakingly pulled data from multiple sources and reviewed individual student records for the report.

With these limitations in mind, here is what the numbers showed for the 2014-15 school year:

• More than 15,500 students newly qualified for an Individualized Education Program, the legally binding plan that outlines the student's required special education services and appropriate academic setting. 
• Of those 15,500 cases, 79 percent were students who qualified for free or reduced-price lunch.
• More than half of newly qualifying students were boys.
• Out of 174,000 total students who qualified for special education services, 60 percent of students were "fully receiving" their mandated services; 35 percent were "partially receiving" services; and 5 percent were not receiving services at all.   

Some of the same conclusions were found in the Citywide Council on Special Education's annual report, released in November.

The non-profit group Advocates for Children also noted that these numbers were in step with what they saw on the ground and heard from families who sought help when children were not receiving mandated special education services.

"Clearly, the city must address the problems delivering timely, appropriate, and legally mandated special education supports," said Kim Sweet, executive director of Advocates for Children, in a statement.

She said it was alarming that the school system did not have an accurate picture of whether schools were in compliance at all. 

"Only once the city is able to identify where it falls short can it adequately remedy the holes left in the educational experiences of so many students with special education needs," said Sweet.

Ever since its 2011 debut, the Special Education Student Information System has been problematic. The city's public advocate recently sued the Department of Education over the data system, calling it a failure.

City education officials fully admitted to the shortcomings of the data system; The mayor's office convened a working group last year to determine whether the data system could be improved or if it should be replaced.