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).
Sasha was more common in the past and has since settled at a lower, steady level. All-time it's been given to 42,801 U.S. babies, the 1,032nd most common name by sound today, peaking at 1,968 in 1988, with 491 in 2025.
By sound, Sasha also includes the spellings Sacha.