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).
Michelle has been slowly declining from its former popularity. All-time it's been given to 1,075,064 U.S. babies, the 772nd most common name by sound today, peaking at 46,038 in 1969, with 727 in 2025.
By sound, Michelle also includes the spellings Michele, Michel, Michell, Mechelle, Machelle.