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).
Joshua
Joshua is down from its peak but still widely used. All-time it's been given to 1,253,882 U.S. babies, the 131st most common name by sound today, peaking at 44,308 in 1989, with 4,773 in 2025.
Joshua has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).