According to the Nevada State Gaming Control Board, the peak in Super Bowl betting at Nevada sportsbooks came in 2018 for Super Bowl LII (Philadelphia Eagles +4½ vs New England Patriots): Just under $158.6 million was wagered in that state alone.
By comparison, the amount bet on the Super Bowl in Nevada for Super bowl XXV (New York Giants +6½ vs Buffalo Bills) was $40.1 million (about $99.85 million adjusted for 2018 value) – a nearly 60% rise over the 27 years.