Batmans post from Singapore states that if you excluded Hubei, the mortality is 0.2%. I would assume thats correct, they can't just make that up.
They made it up. There really is no hard data available - so they have to make it up. They have to make up data for estimating flu mortality too - because you can't know what you can't know. A mild or asymptomatic case of flu isn't recorded as a "case" because it isn't recorded.
Do you think that China would quarantine / travel ban to the extent they have - causing massive economic damage to their economy - if this was "just the flu"?
Singapore said its just the flu, yet they also say they are doing this that and the next thing to fight it.