listenership vs readership

listenership

noun
  • The act of paying attention to a conversation or speech; listening. 

  • The audience that listens to a certain form or genre of audio material (specifically (Internet, radio), an audio broadcast such as a radio program or a podcast). 

readership

noun
  • The role or office of a reader. 

  • The collected readers of a publication. 

How often have the words listenership and readership occurred in a corpus of books? (source: Google Ngram Viewer )