I would tend to agree that it’s likely an aspect of the reasoning for the double circle; a visual pun. I don’t know enough to dispute the Wikipedia article with evidence, however.
If that is the reasoning, I wish they would’ve done something less ambiguous, like -/c or over-lined 100.
The c became a circle is nonsense. The two circles in % denote the two zeros in 100, as they denote the three zeros in thousand/per mille: ‰.
I would tend to agree that it’s likely an aspect of the reasoning for the double circle; a visual pun. I don’t know enough to dispute the Wikipedia article with evidence, however.
If that is the reasoning, I wish they would’ve done something less ambiguous, like -/c or over-lined 100.