Ever since Denver Public Schools decided to embrace school choice in 2007, a debate has raged over whether those reforms helped or hurt the district. A new study by the University of Colorado Denver’s Center for Education Policy Analysis that attempts to answer that question found that, during the 11-year period it dubs the reform years, DPS saw its high school graduation rate increase, academic performance improve among students, and enrollment increase by more than 17,000 students. “This study makes clear that the reforms helped students and strengthened the district,” said Parker Baxter, director of the center and an author of the study, which was released Tuesday.