MADISON, Wis. (AP) — Wisconsin’s college graduation rates have improved and have surpassed the national average. The National Student Clearinghouse Research Center found more than 70% of Wisconsin college students who enrolled in 2015 graduated within six years. The report tracked and compared six-year graduation rates at four-year public universities, two-year public universities and four-year nonprofit universities. It shows about 62% of all college students in the U.S. who enrolled as freshman in 2015 graduated within six years. Madison had the highest six-year graduation rate among UW campuses at about 88%. Parkside had the lowest rate, with 38.6% of 2014 freshman graduating within six years.