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).
Amanda was more common in the past and has since settled at a lower, steady level. All-time it's been given to 792,774 U.S. babies, the 921st most common name by sound today, peaking at 41,909 in 1987, with 601 in 2025.
Amanda has no common alternate spellings by sound.