wake up vs waken

wake up

verb
  • To awake. 

  • To awaken somebody. 

  • To become more aware of a real-life situation; to concentrate on the matter in hand. 

waken

verb
  • To awaken; to cease to sleep; to be awakened; to stir. 

  • To wake or rouse from sleep. 

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