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).
Nyla climbed for decades and has been a steadily popular name ever since. All-time it's been given to 49,536 U.S. babies, the 344th most common name by sound today, peaking at 2,607 in 2019, with 2,133 in 2025.
By sound, Nyla also includes the spellings Nylah, Nailah, Naila. Spellings sometimes heard the same way: Nila, Nayla.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).