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).
Alec is now well below its former popularity. All-time it's been given to 60,138 U.S. babies, the 1,269th most common name by sound today, peaking at 3,588 in 1995, with 284 in 2025.
By sound, Alec also includes the spellings Alek.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).