The least restrictive environment (LRE) mandate suggests a preference for educating students with disabilities in general education settings provided their needs can be met there. This study examined national trends in the educational placements of students with disabilities ages 6 to 17 in the 50 states and the District of Columbia from 1990 through 2015. Data were retrieved electronically from the U.S. Department of Education and the U.S. Census Bureau websites. Cumulative placement rates were then calculated. Findings indicate that from 1990 through 2015, (a) general education placements increased while more restrictive placements decreased, (b) students in secondary schools continued to be placed in more restrictive settings, and (c) the impact of disability categories on national LRE trends varied. Future research is needed to investigate the effect of increased identification rates in specific disability categories on national placement trends and explore how placement practices vary across schools, districts, and states.

中文翻译：

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过去25年中LRE安置率的趋势

最低限制环境（LRE）要求表明，如果可以在当地满足残障学生的需求，则倾向于在普通教育环境中对残障学生进行教育。这项研究调查了1990年至2015年美国50个州和哥伦比亚特区6-17岁残障学生的教育安置的全国趋势。数据通过电子方式从美国教育部和美国人口普查局网站检索。然后计算累积放置率。调查结果表明，从1990年到2015年，（a）通识教育职位增加，而限制性更强的职位减少，（b）中学学生继续处于限制性更强的环境，（c）残疾类别对国家LRE趋势的影响多变。