The 2008 Research Assessment Exercise returned 26% of the 1225 staff submitted as being world-leading (4*) and a further 47% as being internationally excellent (3*). The 2008 Research Assessment Exercise also showed five subjects – Pure Mathematics, Epidemiology and Public Health, Chemical Engineering, Civil Engineering, and Mechanical, Aeronautical and Manufacturing Engineering – were assessed to be the best[clarification needed] in terms of the proportion of internationally recognised research quality.