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).
Demi
Demi has been climbing in recent years. All-time it's been given to 14,921 U.S. babies, the 804th most common name by sound today, peaking at 914 in 2020, with 811 in 2025.
Demi has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).