For the first time since 2003 under the federal No Child Left Behind law, the Philadelphia School District has seen a majority of its students score at the proficient or advanced level on standardized tests, according to a recent report.

The data were taken from when schools were plush with cash and Superintendent Arlene Ackerman's reform plan was being faithfully carried out.

But now, as the district works to close a $629 million deficit through planned teacher layoffs, larger class sizes and cuts to arts and transportation, it's possible that the progress the district has made in recent years could revert.

That reality didn't escape James Lyons, chairman of the Accountability Review Council tasked with monitoring the district's reform efforts, who warned the School Reform Commission yesterday to stay the course.

"We hope that as you wrestle with the challenges brought on by the economic downturn that you will keep the school reform high up on your agenda," he said. "And as you make cuts that would be strategic, you [need to] keep the school community informed."

Lyons gave an encouraging report of the gains the district has made. Among them, all categories of students have shown academic gains. The council's report is conducted yearly and informs the commission of the progress the district is making under No Child Left Behind, the 2001 federal law aimed at improving failing schools.

This year, the council, along with the education and research group Research for Action, also looked at the progress of the district's Renaissance Schools Initiative, which seeks to turn around failing schools by converting them into outside-managed charters or Promise Academies.

The report found that between 2002 and 2010, the percentage of district schools that made Adequate Yearly Progress rose from 9 percent to 59 percent.

In 2010, 158 district schools made sufficient progress, up from 51 schools in 2007, according to the report.

Though the rest of the state continued to have a higher percentage of students scoring at proficient and advanced than Philadelphia, district students in grades four through eight and grade 11 achieved higher reading scores than students in the rest of the state in 2009 and 2010, the report states.

In math, the district's students also outpaced students in the rest of the state in grades three, four, six, seven, eight and 11.

"These are good news items we want to lift up to you this afternoon," Lyons said. However, he added, the district still has work to do.