The cruise ship showed a ~50% symptomatic rate, so any stats based on symptomatic patients are probably only off by a factor of 2. Note that both South Korea a

The cruise ship showed a ~50% symptomatic rate, so any stats based on symptomatic patients are probably only off by a factor of 2. Note that both South Korea and China outside Wuhan do extensive contact tracing and testing of people an infected individual can be determined to have interacted with, so they pick up a good deal of asymptomatic cases too.