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).
Shirley
Shirley is now well below its former popularity. All-time it's been given to 701,648 U.S. babies, the 1,980th most common name by sound today, peaking at 43,141 in 1935, with 133 in 2025.
By sound, Shirley also includes the spellings Shirlee.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).