How to read the band →
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).
William
William has been easing down from its peak but is still widely used. All-time it's been given to 4,222,553 U.S. babies, the 20th most common name by sound today, peaking at 67,197 in 1947, with 10,572 in 2025.
By sound, William also includes the spellings Willian, Wm.
Rising