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).
Gage has been slowly declining from its former popularity. All-time it's been given to 70,420 U.S. babies, the 1,245th most common name by sound today, peaking at 3,508 in 2009, with 269 in 2025.
By sound, Gage also includes the spellings Gauge, Gaige.