Do you have a source for that number? I'm asking, because I somewhat feel like this number is supportive of my assumption that they test the wrong people.
I understand that the symptoms are pretty ordinary and there are a lot of pathogens which could cause it. And you're right, all I have are anecdotes.
My own cough is still going on for almost two weeks now. I'm pretty sure that I got it from a coughing man on my commuting train. Four days later I had a sore throat and on the fifth day I had this cough. If this person was tested, and was positive, there's no chance they could find me.
I don't say that to diminish the importance of testing, my point is that the anecdotes aren't necessarily very informative.