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).
Scarlett has climbed over the years and is holding near its high. All-time it's been given to 135,254 U.S. babies, the 71st most common name by sound today, peaking at 9,006 in 2016, with 6,428 in 2025.
By sound, Scarlett also includes the spellings Scarlet, Scarlette.