Indeed, I believe the quote is closer to something like this (please don't make me dig it up in Aikido Shugyo, I made zero notes in that book ._.'): In a real fight, 70% is atemi / in a real fight, 70% of Aikido is atemi. Or something like that. O Sensei certainly didn't state that 70% of Aikido is Atemi.
Semantics. "...in a real fight, 70% of Aikido is atemi..." was what I was referring to
And that's good enough for me. don't want to over think this.