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).
Tru has been climbing in recent years. All-time it's been given to 10,989 U.S. babies, the 605th most common name by sound today, peaking at 1,204 in 2024, with 1,127 in 2025.
By sound, Tru also includes the spellings True.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).