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).
Ruben is now well below its former popularity. All-time it's been given to 161,338 U.S. babies, the 680th most common name by sound today, peaking at 2,169 in 1990, with 946 in 2025.
By sound, Ruben also includes the spellings Reuben, Rubin, Rueben.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).