The problem here is that the OP, Habitual_Ritual, is not being counted as a "person who posted." For some reason you're only counting the persons who respond, when the title simply stipulates "persons who post." OP means "original poster." He is someone who has posted. He was the first person to post. I think that makes Clare number eight, not seven.
I would be therefore "Number 9."
Fortunately, Habitual_Ritual is still an active forum member, so he can be called on to clarify in the event of a disputed win.