There’s no change at the top: Market leader KUSA-Channel 9 remains dominant across all time periods at the close of local TV’s May ratings sweep. But there’s a new No. 2 in town: KDVR-Channel 31 scored historic wins, beating out KCNC-Channel 4 at 6 a.m., 5 p.m. and 10 p.m. weekdays among viewers age 25-54, the traditional news demographic. (For spinning purposes, there’s a tie for second place if you count Monday through Sunday at 10 p.m., with Fox31 and KCNC both scoring a 1.17 rating.