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).
Mark
Mark is now well below its former popularity. All-time it's been given to 1,507,809 U.S. babies, the 471st most common name by sound today, peaking at 61,455 in 1960, with 1,578 in 2025.
By sound, Mark also includes the spellings Marc.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).