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).
Nia
Nia is now well below its former popularity. All-time it's been given to 30,222 U.S. babies, the 1,017th most common name by sound today, peaking at 1,236 in 2001, with 464 in 2025.
By sound, Nia also includes the spellings Niya. Spellings sometimes heard the same way: Nya, Nyah.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).