Please answer a question about the following article about Washington University in St. Louis:

In the 2015 US News & World Report America's Best Graduate Schools, the law school is ranked 18th nationally, out of over 180 law schools. In particular, its Clinical Education Program is currently ranked 4th in the nation. This year, the median score placed the average student in the 96th percentile of test takers. The law school offers a full-time day program, beginning in August, for the J.D. degree. The law school is located in a state-of-the-art building, Anheuser-Busch Hall (opened in 1997). The building combines traditional architecture, a five-story open-stacks library, an integration of indoor and outdoor spaces, and the latest wireless and other technologies. National Jurist ranked Washington University 4th among the "25 Most Wired Law Schools."

Where is the Washington University School of Law ranked in the 2015 US News & World Report America's Best Graduate Schools?
18th