clientele vs listenership

clientele

noun
  • The body or class of people who frequent an establishment or purchase a service, especially when considered as forming a more-or-less homogeneous group of clients in terms of values or habits. 

listenership

noun
  • 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). 

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

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