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).
Astrid
Astrid has been climbing in recent years. All-time it's been given to 14,153 U.S. babies, the 789th most common name by sound today, peaking at 822 in 2024, with 818 in 2025.
Astrid has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).