The percentage of high schools that rated an A under the city’s controversial grading system increased by 5 points from last year, to 45 percent.
At the same time, the proportion of C and D schools jumped to 26 percent, a gain of 11 percentage points since last year.
Only one school — Peace and Diversity Academy in The Bronx — earned a dreaded F, down from six schools last year.
Overall, 139 of 311 high schools that were graded by the city received A’s, 92 received B’s, 58 got C’s and 21 D’s.
School officials said the increase in C and D scores resulted from their setting the passing bar higher this year based on credit accumulation, Regents exam results and graduation rates.
“Despite [the higher bar], 5 percent more of our schools got an A,” said Schools Chancellor Joel Klein. “Overall, I think it’s been a strong year for our high schools’ progress.”
Klein and Mayor Bloomberg introduced the grading system three years ago as a way to hold school leaders and educators accountable and to better inform parents and students of how their schools are doing.
Schools that earn consecutive grades of C or below are at risk of principal changes or even closure — which has hap pened at dozens of schools in the past two years.
The high-school grades showed a much more balanced distribution than the grades released for elementary and middle schools last month, which raised eyebrows after 97 percent of schools were rated with As or Bs.
The skewed ratings were blamed on unusually high gains in state math and reading scores.
But United Federation of Teachers President Michael Mulgrew said even the high-school rating system wasn’t measuring schools accurately.
He said many of the lower-rated schools — such as Jamaica HS in Queens, which earned a D — are unduly burdened with challenging kids.
Mulgrew also bristled at a chart produced by the city showing that the smaller high schools opened under Bloomberg since 2002 were faring better than others, even as several of the newer schools rated D’s and the lone F.
“I don’t like when you try to draw distinctions when you’re responsible for all of the schools but you have a vested interest in trying to tell people that the schools you created are doing well,” he said.
Even with questions about the grading system, however, students, parents and educators had strong reactions to the appraisals.
At New Dorp HS on Staten Island, which clawed its way from a low C grade in the pilot program three years ago to its first-ever A this year, the feeling was elation.
“My staff was so thrilled, my kids were cheering today — it was so much fun,” said Principal Deirdre DeAngelis. “It did a lot for the self-esteem of the school.”
By contrast, at the Choir Academy of Harlem — which slid from a C to a D — parents who had complained about the school said at least the public results might bring more scrutiny to the program.
“It doesn’t really surprise me at all that the school got a D,” said one parent, who lamented that the choir program had deteriorated, kids weren’t wearing their uniforms and discipline was a growing problem. “It used to be a really good school — now parents are pulling their sons out.”