date=2020-03-212020-03-142020-03-212020-03-282020-04-042020-04-112020-04-182020-04-252020-05-022020-05-092020-05-162020-05-232020-05-3000.0020.0040.0060.0080.01proportionProportion of Population Tested Positive for COVID-19 by County in the U.S.