No, we don't.
While you may be right, we don't "know it for a fact".
The data from China, especially Wuhan, aren't super useful, because they may be doctored, we don't know anything about how wildely the virus circulated or what other complications the people who died might have had. There's 600 dead, ~29k confirmed in Wuhan, but "confirmed" can mean tested positive and mostly quarantined at home, or hospitalized. There's likely a lot of infections that weren't tested yet. Tl;dr - we don't know what the CFR is.
We do know, however, what the data are outside of China. And there are 2 deaths so far, at least one of which was with other underlying complications. It's too soon to tell, but again, we don't "know for a fact" jack shit.