Cambridge school officials released figures last night showing continued disparities between black, Latino and white students at every grade level in practically every aspect of academic performance in the Cambridge school system.

The comprehensive report--detailing test scores, drop-out and suspension rates, and other indicators of academic success--showed that black students in fourth grade are half as likely as white students to be considered proficient readers. It also showed that nearly half of black students at Cambridge Rindge and Latin School (CRLS) failed at least one class last year.

The report noted that students who participate in the government-funded free lunch program, special education students and students with limited English proficiency all do worse than the district average on standardized tests.

Overall, the statistics in the report showed little improvement from last year or from the previous decade of reports that have come before the school committee.

Latino students generally do as poorly, and in some academic areas, worse, than black children.

But Asian students are consistently the top performers in almost all academic categories.

The achievement gap "has gotten progressively worse. The system has gotten progressively more arrogant," said Kathy A. Reddick, president of the Cambridge branch of the National Association for the Advancement of Colored People (NAACP).

"[The school district has]been negligent. They love to blame the families," she added.

Reddick and the NAACP have issued what they term a "call to action" to improve education in the city.

They plan to create a task force that they say will hold regular meetings and work to keep school policymakers accountable. The group also plans to release their own version of the district's data report, focusing on numbers that highlight the achievement gap between black and white students.

Even district administrators acknowledged that test scores show a persistent discrepancy in performance. But they said they are working on ways of fixing the problems system-wide.

Parents, students and administrators must "look at structures of inequity that exist within our [school] system," said Lenora M. Jennings, who directs the district's office of student achievement.

School district administrators are finalizing a district-wide improvement plan that Jennings said would provide more than a "band-aid approach" to erasing inequities in Cambridge schools. The plan aims to standardize curriculum and improve teaching across the district.

For example, Jennings said, in response to data showing a continued gap in reading scores for students in grades 3 to 8, administrators have developed a comprehensive two-year training program for language arts teachers. She said district officials are also finalizing so-called "benchmarks" that spell out district-wide performance standards in language arts.

Administrators and school committee members have identified the improvement plan as a virtual cure-all for the district.