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).
King has fallen well below its former popularity. All-time it's been given to 40,257 U.S. babies, the 546th most common name by sound today, peaking at 2,921 in 2017, with 884 in 2025.
By sound, King also includes the spellings Kyng.