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).
Deborah was more common in the past and has since settled at a lower, steady level. All-time it's been given to 1,334,536 U.S. babies, the 1,176th most common name by sound today, peaking at 105,671 in 1955, with 422 in 2025.
By sound, Deborah also includes the spellings Debra, Debora, Debrah, Debbra.