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).
Helena
Helena has stayed fairly steady in American naming for generations. All-time it's been given to 40,412 U.S. babies, the 834th most common name by sound today, at an all-time high of 841 in 2025.
Helena has no common alternate spellings by sound.
Rising