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).
Ivan
Ivan climbed for decades and has been a steadily popular name ever since. All-time it's been given to 150,787 U.S. babies, the 328th most common name by sound today, peaking at 3,479 in 2004, with 2,240 in 2025.
Ivan has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).