Here’s what New York City Mayor Bill de Blasio said upon the news, released Friday, that the percentage of students who passes state assessments in reading jumped to 38%, almost 8 points higher than last year:

“These results represent important progress and outline real improvements across each borough of our city. We congratulate our students, families and devoted educators for this critical step forward.” His Education Chancellor Carmen Farina added exultantly the following Monday, “This has been a three-day celebration, I can’t stop smiling.”

Here’s what Mayor de Blasio and Chancellor Farina didn’t say: this “critical step forward” that warranted a “three-day celebration” was driven almost entirely by the city’s charter schools, which serve  95,000 children. There, student proficiency rates in reading  leapt up to 43% from last year’s passing rate of 29%. Charter students also outperformed the traditional sector in math, 49% to 36%, even though the charters serve a higher at-risk enrollment.

As the Post points out, “nearly half of the city’s 20 top-scoring public schools for grades 3-8 were charters — where students are mainly black and Hispanic. A single charter network, Success Academy, had the top five schools in the entire state in math, and two of the top five in English.”

To put this in perspective, remember that charter schools serve less than 9% of New York City public school students.

Mayor de Blasio and Chancellor Farina might want to take a few minutes from their celebration to rethink their resistance to charter school expansion, as well as graciously acknowledge that the city’s great success was facilitated by their predecessors Mike Bloomberg and Joel Klein.

After all, it was the Bloomberg Administration that added 173 charter schools to the city’s then woefully small menu of  options for low-income, mostly minority children trapped in chronically-failing schools. One way Bloomberg and Klein seeded the expansion was by proactively recruiting top-notch charter operators and creatively offering these alternative schools space in under-enrolled buildings (also called colocations) and helping with rent payments.

What does Mayor de Blasio think about the practice of co-location within the city’s crazy real estate market?   At a 2014 press conference, just a year into his term,  he told reporters,” Look, I’m not going to mince words about what I feel about how the Bloomberg Administration made decisions on co-locations. I think it was abhorrent.”

Ah, but Mayor, if Bloomberg and Klein didn’t make the decisions they did about co-locations, your 2016 test scores wouldn’t be anything to celebrate.  If you’d won your  feud with Success Academy founder Eva Moskowitz and stymied her charter expansion, your congratulations might be a bit more tepid. (At Success Academy, by the way,  94% of its students passed  the math exam and 82% passed reading.)

Yet there’s room for hope. When queried about charter performance, de Blasio owned,  “we’re all in this together. We’re thrilled to see schools of all kinds improve.” Now that’s an attitude improvement that parents across the city would celebrate.