Between the 2003–04 and 2011–12 school years, the percentage of public schools reporting that they required that students wear uniforms increased from 13 to 19 percent. In 2011-12, the percentage of public secondary schools who reported requiring that students wear uniforms (12 percent) was lower than the percentages of elementary schools (20 percent) and combined schools (30 percent) with such a requirement.
Higher percentages of public city schools than of public schools in suburban, town, and rural areas reported requiring students to wear uniforms. Also, many safety and security measures tended to be more prevalent in high-poverty public schools (where 76 percent or more of students are eligible for free or reduced-price lunch) than in low-poverty schools (where 25 percent or less of students are eligible for free or reduced-price lunch) during the 2011–12 school year. For example, 47 percent of high-poverty public schools reported requiring school uniforms, compared to 6 percent of low-poverty public schools.