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).
Rodrigo
Rodrigo has stayed fairly steady in American naming for generations. All-time it's been given to 27,759 U.S. babies, the 937th most common name by sound today, peaking at 1,177 in 2007, with 614 in 2025.
Rodrigo has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).