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).
Griffin
Griffin climbed for decades and has been a steadily popular name ever since. All-time it's been given to 51,809 U.S. babies, the 461st most common name by sound today, peaking at 1,750 in 2023, with 1,648 in 2025.
Griffin has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).