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).
Keon climbed for decades and has been a steadily popular name ever since. All-time it's been given to 21,006 U.S. babies, the 985th most common name by sound today, peaking at 659 in 2002, with 459 in 2025.
By sound, Keon also includes the spellings Keyon, Keion, Kiaan.