Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Randy was more common in the past and has since settled at a lower, steady level. All-time it's been given to 368,283 U.S. babies, the 1,505th most common name by sound today, peaking at 17,243 in 1956, with 232 in 2025.
By sound, Randy also includes the spellings Randi, Randee.