More high school students are hitting the books and getting their degrees within four years, data from the National Center for Education Statistics show. But not every state is part of that positive trend, the Lookout reports. About 74.7 percent of high school students in the class of 2007-08 graduated on time, up from 72 percent of the class of 2002. But on-time graduation rates dropped by more than 5 percent in Utah, the District of Columbia, and Nevada over the same period…