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).
Gloria was more common in the past and has since settled at a lower, steady level. All-time it's been given to 417,018 U.S. babies, the 1,143rd most common name by sound today, peaking at 12,662 in 1947, with 437 in 2025.
Gloria has no common alternate spellings by sound.