The New York Times is releasing a series of data files with cumulative counts of ' 'coronavirus cases in the United States, at the state and county level, over time.The data begins ' 'with the first reported coronavirus case in Washington State on Jan. 21, 2020.

' 'The data is the product of dozens of journalists working across several time zones to monitor news ' 'conferences, analyze data releases and seek clarification from public officials on how they categorize ' 'cases.

Confirmed cases are patients who test positive for the coronavirus. ' 'A case is consider confirmed when it is reported by a federal, state, territorial or local government ' 'agency.

For each date, there is the cumulative number of confirmed cases and deaths ' 'available as reported that day in that county or state. All cases and deaths are counted on the date they ' 'are first announced.

In some instances, the data is reported from multiple counties or ' 'other non-county geographies as a single county. For instance, there is a single value for New York City, ' 'comprising the cases for New York, Kings, Queens, Bronx and Richmond Counties.

Cities ' 'like St. Louis and Baltimore that are administered separately from an adjacent county of the same name ' 'are counted separately.

Many state health departments choose to report cases ' 'separately when the patient's county of residence is unknown or pending determination. ' 'In these instances, the county name is recorded as 'Unknown' As more information about ' 'these cases becomes available, the cumulative number of cases in 'Unknown' counties may ' 'fluctuate.

Sometimes, cases are first reported in one county and then moved to ' 'another county. As a result, the cumulative number of cases may change for a given county.

All cases for the five boroughs of New York City (New York, Kings, Queens, Bronx and Richmond ' 'counties) are assigned to a single area called New York City. There is a large jump in the number of ' 'deaths on April 6th due to switching from data from New York City to data from New York state for ' 'deaths.

For all New York state counties, starting on April 8th the New ' 'York Times is reporting deaths by place of fatality instead of residence of individual.

Starting April 12th, the New York Times case count excludes cases labeled by the state as ' ''Non-Georgia Resident' leading to a one day drop in cases. These cases were previously included as ' 'cases with 'Unknown' county.

Four counties (Cass, Clay, Jackson and Platte) overlap the municipality of Kansas City, Mo. The cases and deaths for these four counties are ' 'only shown for the portions exclusive of Kansas City. Cases and deaths for Kansas City are reported ' 'as their own line.

Counts for Alameda County include cases and deaths from Berkeley ' 'and the Grand Princess cruise ship.

Counts for Douglas County include cases brought ' 'to the state from the Diamond Princess cruise ship.

All cases and deaths for ' 'Chicago are reported as part of Cook County.

Counts for Guam include cases reported ' 'from the USS Theodore Roosevelt.