I caution against reading too much into the South Korean fatality rates because many of the patients are younger and generally healthy (http://www.koreaherald.com/view.php?ud=20200303000714).

Whatever the global mortality rate shakes out to be in the long-run, it’s impossible to ignore the fact that this virus killed nearly a dozen nursing home residents in the span of 2 weeks. There’s a lot we don’t understand about COVID-19, certainly more than a single metric can tell us.

Based on what we’re seeing in the state of Washington and around the world, it’s safe to say that older patients are at higher risk for developing respiratory failure. Beyond that, it’s simply way too early to draw conclusions.