6 here, too, but I have NO idea about the content (I skimmed it). I assume it's from proofreading so much as an attorney and in law school. Like someone else mentioned, my proofreading skills are not always as effective on my own writing though.
Even when the damn test instructed me to go back and find the three I missed, I still didn't see them. Although, I read each word, and didn't look at letters, specifically... yeah, yeah, I'm just making excuses. I should have known, I'm not the most observent chic out here.