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).
Sincere
Sincere has held a fairly steady level of use. All-time it's been given to 15,375 U.S. babies, the 829th most common name by sound today, peaking at 825 in 2022, with 681 in 2025.
By sound, Sincere also includes the spellings Syncere.
Rising