But that 20% is growing, and the amount of newspaper digitization projects are growing also. Whether they be commercial subscription sites, state wide projects, or small library digitization projects for just one newspaper, they all add up.
Here is a list of new digitization efforts that are either in progress or are recently completed. The link will take you to an article that describes in more detail the status of the project.
Delaware - Delaware Gets New Online Historic Newspapers
Georgia - When formal records fail, newspapers can save the day
Indiana - WPA indexing keeps century-old news at fingertips
Indiana - IU Southeast receives grant to microfilm, digitize issues of student newspaper
Indiana - Indiana's Hoosier Chronicles Adds 17,500 More Online Historical Newspaper Issues
Iowa - 5 Local Projects Land State Historical Grants
Iowa - Digital newspapers now available
Maine - Maine State Library receives grant for newspaper project
Massachusetts - Library completes first phase of digitizing local newspapers
Missouri - Paper's archives now available to 1880s
Nebraska - Museum aims to preserve print history
Nebraska - From microfilm to the internet: SML working to convert microfilm into searchable database
New Jersey - Rutgers to bring historic N.J. newspapers alive online
New York - Newly Added Staten Island Online Historical Newspapers
Pennsylvania - Ledger archives will soon be available at library, historical society
Pennsylvania - Around the region, Aug. 17, 2016 - Pottsville
South Dakota - Six more historic newspaper titles now available online
Utah - Archiving effort back underway
Hopefully the paper or location is in the area of your research!
I'm sure there are more projects underway - these are just some that have written articles about them.
If you know of more - please let us know in the comments.