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).
Eric has dropped sharply from its peak but is still widely used. All-time it's been given to 1,153,140 U.S. babies, the 233rd most common name by sound today, peaking at 29,137 in 1980, with 2,758 in 2025.
By sound, Eric also includes the spellings Erik, Erick, Erich, Aric, Arik.