Students from disadvantaged backgrounds are doing better in charter schools than in traditional public schools.

According to the California Charter Schools Association’s recent report on the status of the state’s charter school movement, more than a quarter of all charter school students who are black, Latino or learning English – students who’ve historically fallen behind – attend the state’s most “outperforming” public schools.

That’s a way of saying those students do better than predicted, based on their parents’ income or education level.

How are charter schools actually performing overall? Well, better than in the past. And they continue to grow. Between 2007 and 2012, charter school enrollment in California nearly doubled.

Its first annual report in 2011 showed what CCSA called a daunting challenge: There were a lot of charters doing really well, many doing really poorly and not many in the middle.

This year’s report paints a brighter picture. The charter schools that were performing well maintained, and some of the struggling schools have since been closed. Weeding out the failing charters is a part of growing the charter school community, said CCSA President Jed Wallace.

CCSA has helped close 143 schools since 2009, he said.

“During that period we’ve seen public support for charter schools become even higher. This speaks to the fact that the public is embracing a new form of public schools that are clearly far more accountable than the traditional system,” Wallace said.

In terms of performance, the local numbers mirror the statewide pattern. Of the 38 San Diego Unified charter schools accounted for in the most recent report, which looked at data from the 2012-2013 school year, a higher percentage of charters than traditional public schools were performing in the top 5 percent of all public schools statewide.

That comes with a caveat, though. To compare schools, CCSA isn’t just using schools’ API scores, which are composite scores based on standardized test results. By that measure alone, charter schools are slightly behind traditional public schools in San Diego Unified.

Instead, CCSA uses what it calls a Similar Students Measure. It factors in things like average parent education level, poverty and race to come up with a predicted API score. Then, it takes the predicted score and compares it to the school’s actual API.

CCSA is then able to determine which schools are “underperforming” or “outperforming,” based on their predicted API scores.

That’s why one of the highest-ranking San Diego Unified charter schools in San Diego Unified, using the Similar Students Measure, is Arroyo Paseo Charter High. That school scored 704 API score, which is below the district average.

But the school’s demographics show it has a high percentage of students who’ve traditionally fallen behind. About 14 percent of its students are black, 75 percent are Latino and almost 90 percent received subsidized lunch.

Another high-ranking school, Preuss School at UCSD, had similar demographics and an API score of 888 – well above the district’s average that year. The Preuss School was recently ranked as one of the best high schools in the nation by U.S. News & World Report.

“While we’ve come a long way in improving charter school performance in California, we know we still have a long way to go,” Wallace said. “But we think it it’s important to highlight the improvements we’ve made in the last five years, especially during a time of explosive growth in charter school enrollment, and a severe funding crisis.”