couch potato vs slugabed

couch potato

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

slugabed

noun
  • A lazy person who lies in bed after the usual time for getting up; a sluggard. 

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