couch potato vs idler

couch potato

noun
  • A person who spends a lot of time sitting or lying down, often watching television, eating snacks or drinking alcohol. 

idler

noun
  • One who idles; one who spends his or her time in inaction. 

  • One who idles; a lazy person; a sluggard. 

  • A mechanical device such as a pulley or wheel that does not transmit power, but supports a moving belt etc. 

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