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).
David is down from its peak but still widely used. All-time it's been given to 3,689,613 U.S. babies, the 66th most common name by sound today, peaking at 86,454 in 1955, with 6,801 in 2025.
David has no common alternate spellings by sound.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).