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).
Elaine has been climbing in recent years. All-time it's been given to 267,657 U.S. babies, the 734th most common name by sound today, peaking at 7,170 in 1947, with 1,047 in 2025.
By sound, Elaine also includes the spellings Elayne.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).