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).
Bentley is now well below its former popularity. All-time it's been given to 68,701 U.S. babies, the 360th most common name by sound today, peaking at 6,676 in 2012, with 1,914 in 2025.
By sound, Bentley also includes the spellings Bentlee.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).