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).
Cynthia
Cynthia is now well below its former popularity. All-time it's been given to 719,556 U.S. babies, the 1,373rd most common name by sound today, peaking at 39,513 in 1957, with 260 in 2025.
By sound, Cynthia also includes the spellings Cinthia.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).