I think there is little accurate, published data on the actual percentage of infections needing ICU level care. I suspect that there may be many infections with minor symptoms that mimic those of colds and other upper respiratory infections. Some patients have tested positive and have not reported any significant symptoms. So the percentage of cases with serious symptoms may be uncertain at this time.
The reports from clinicians in China indicate the situation with the serious cases, and their data is not reassuring. The load on the hospitals is intense, and long lasting.
I based my comments on the numbers reported from China. And we “know” they are light.
The 2-3% reported is a simple calc. The real rate is higher I guess.