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).
Oscar is now well below its former popularity. All-time it's been given to 217,409 U.S. babies, the 420th most common name by sound today, peaking at 3,720 in 2006, with 1,713 in 2025.
By sound, Oscar also includes the spellings Oskar.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).