Assuming for a moment that the test websites didn't give a specific reason to trust them more or less than any other website operator. This means that if your website has significantly more than those 9% consent, you're either perceived as very trustworthy, or your GDPR banner is confusing (or, less charitably, deceiving) users. Would be interesting to see how the consent rates for big offenders like techcrunch, news…
So I guess exactly zero visitors opt out there in the intended way. So 100% "opt-in".
I tried to opt-out from all to see how many cookies would be set anyway but gave up after 5 minutes.