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).
Zara has been climbing in recent years. All-time it's been given to 21,659 U.S. babies, the 515th most common name by sound today, peaking at 1,466 in 2022, with 1,456 in 2025.
By sound, Zara also includes the spellings Zehra. Spellings sometimes heard the same way: Zaira.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).