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).
Mario
Mario is now well below its former popularity. All-time it's been given to 152,403 U.S. babies, the 785th most common name by sound today, peaking at 2,974 in 1980, with 721 in 2025.
Mario has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).