The University of Colorado at Boulder ranks fifth in the nation for the number of graduates currently serving as Peace Corps volunteers, according to 2002 rankings released today. For several years, including last year, the university ranked second in the nation in numbers of volunteers. In 2002, the University of Wisconsin at Madison ranked first, with 96 volunteers, followed by the University of Michigan at Ann Arbor with 76, the University of California at Berkeley with 70, the University of Texas with 69 and CU-Boulder with 64.