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).
Sandra
Sandra is now well below its former popularity. All-time it's been given to 878,223 U.S. babies, the 1,642nd most common name by sound today, peaking at 34,852 in 1947, with 188 in 2025.
Sandra has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).