I'mma be honest, if I was living in a country where it was common knowledge that slandering the government in anyway got you disappeared, I'd rate them highly on any study put in front of me :/
I know I'm going to have comments telling me I don't know what I'm talking about, and that's ok. I've enough friends in China, and from China, who have talked about this kind of thing to understand that this graph could represent the feelings of the people, but likely doesn't.