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).
Annabella has been slowly declining from its former popularity. All-time it's been given to 21,775 U.S. babies, the 1,511th most common name by sound today, peaking at 1,865 in 2014, with 244 in 2025.
By sound, Annabella also includes the spellings Anabella.