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).
Aisha has been climbing in recent years. All-time it's been given to 30,149 U.S. babies, the 700th most common name by sound today, peaking at 1,571 in 1977, with 1,022 in 2025.
By sound, Aisha also includes the spellings Aysha.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).