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).
Gerald was more common in the past and has since settled at a lower, steady level. All-time it's been given to 500,797 U.S. babies, the 1,691st most common name by sound today, peaking at 12,794 in 1942, with 194 in 2025.
By sound, Gerald also includes the spellings Jerald, Jerrold, Jerold, Gearld, Gerold. Spellings sometimes heard the same way: Garold.