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).
Trevor
Trevor is now well below its former popularity. All-time it's been given to 168,086 U.S. babies, the 1,060th most common name by sound today, peaking at 6,848 in 1998, with 413 in 2025.
By sound, Trevor also includes the spellings Trever.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).