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).
Henry has been climbing back after years of decline. All-time it's been given to 779,551 U.S. babies, the 17th most common name by sound today, at an all-time high of 12,135 in 2025.
By sound, Henry also includes the spellings Henri.