NPR is a PUBLIC radio station...PUBLIC.  It is not a corporate shill radio station...and states individually run various and sundry stations (some solely news and classic music).  

What is their listener ratio to corporate right-wing ratios?  Right...not even close!!!

And you want to use wikipedia as a source?  Good grief.  Go to your local library and have your librarian teach you how to ascertain reliable and up-to-date sights that reflect actual scientific research.