The assumption is that the testing population is currently biased towards more serious cases (e.g. if you are in the hospital you get tested. but if you are in the hospital, you have severe symptoms => higher % will die). On the other hand you could have an entire family of 6 people under the same roof not being tested but all positive. Italy thought something similar and tested an entire village. Loads showed no symptoms and tested positive.
Hence you will have X% of 60%. Question now is what the X is. But 9% seems to be the super pessimistic upper bound.
The assumption is that the testing population is currently biased towards more serious cases (e.g. if you are in the hospital you get tested. but if you are in the hospital, you have severe symptoms => higher % will die). On the other hand you could have an entire family of 6 people under the same roof not being tested but all positive. Italy thought something similar and tested an entire village. Loads showed no symptoms and tested positive.
Hence you will have X% of 60%. Question now is what the X is. But 9% seems to be the super pessimistic upper bound.