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).
Sevyn
Sevyn has been climbing in recent years. All-time it's been given to 6,239 U.S. babies, the 731st most common name by sound today, peaking at 911 in 2024, with 908 in 2025.
Sevyn has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).