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).
Craig was more common in the past and has since settled at a lower, steady level. All-time it's been given to 306,579 U.S. babies, the 2,317th most common name by sound today, peaking at 10,905 in 1960, with 102 in 2025.
By sound, Craig also includes the spellings Kraig.