“Students in Roman Catholic schools in the Chicago area tend to make better gains on test scores over four years than the average public and private school students, national test data released Wednesday show. This year’s test scores also show Catholic school students here performing above the national average, in some cases far above. In seventh-grade language arts, for example, students scored at the 78th percentile; the 50th percentile is average. The lowest rank was in third-grade science, where students scored at the 60th percentile.”