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).
Ronan has climbed over the years and is holding near its high. All-time it's been given to 31,432 U.S. babies, the 394th most common name by sound today, peaking at 2,103 in 2022, with 2,045 in 2025.
By sound, Ronan also includes the spellings Ronin.