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).
Clark
Clark has stayed fairly steady in American naming for generations. All-time it's been given to 56,803 U.S. babies, the 692nd most common name by sound today, peaking at 1,032 in 2025, with 1,032 in 2025.
By sound, Clark also includes the spellings Clarke.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).