SEATTLE (AP) – The Tacoma school district took a well-earned bow on Tuesday at a celebration of record-breaking graduation rates. In four years, Washington state’s second-largest school district has gone from graduating 55 percent of students 2010 to beating the state average with a 78 percent graduation rate.

Improvement was seen at every high school and in every ethnic group, with the biggest increases among low-income and minority students. District Superintendent Carla Santorno said she believes Tacoma is on its way to meeting its goal of graduating 85 percent of its students by 2020.

Santorno called the numbers she announced Tuesday powerful and credited caring teachers and staff members who keep a close eye on students and data for the improvements over the past few years. “We still have much more work to do on our achievement gaps, but we’re heading in the right direction,” she said.

In the past two years, black students, who make up about 20 percent of the district’s enrollment, improved their high school graduation rate from 59.4 percent to 73.8 percent. The statewide graduation rate for black students in 2013 – the most recent year for which statewide data is available – was 65.4 percent.

The graduation rate for Native American students increased from 48.6 percent in 2012 to 68.2 percent in 2014. The statewide number was 52.5 percent in 2013.

Hispanic students went from a 2012 graduation rate of 57.5 percent to 67 percent in 2014. Hispanic students represent more than 17 percent of the district’s student population. The statewide graduation rate for Hispanic students was 65.6 percent in 2013.

Low-income students, who qualify for free- or reduced-price school meals, saw their graduation rate increase from 61.2 percent in 2013 to 70.5 percent in 2014. The statewide number for low-income students was 64.6 percent in 2013.

In 2007, a national researcher labeled all Tacoma’s comprehensive high schools as “dropout factories” in an Associated Press story.

The district initiatives aimed at improving graduation rates and decreasing drop-out rates included:

–Aggressively signing up middle school students for the statewide College Bound Scholars program that gives money for college to low-income students who graduate from high school.

–Eliminating fees for SAT, PSAT and Advanced Placement tests.

–Increasing the rigor of high school classes.

–Offering more education options for students, including the School of the Arts, and the Science and Math Institute.