The University of Colorado at Boulder has enrolled its largest freshman class ever this fall with 4,281 first-year students entering campus, contributing to a total enrollment of 25,125. The total is up slightly from fall 1997 enrollment of 25,109. The enrollment increase continues a trend of planned, moderate increases on the Boulder campus since 1995, when total enrollment was 24,440, according to Lou McClelland, director of institutional analysis. CU-Boulder's highest ever enrollment was 25,571 in 1991.