The reason I ask this question is because the daily reporting of "new cases" is an almost meaningless statistic directly related to the number of tests performed. I would like to know approximately how many people in the U.S. have been exposed to the Covid-19 virus. If, for example, 10% have been exposed, that represents about 33 million people. In that case, what is the purpose of counting them one by one until everyone has been tested? NBC Nightly News?