spring up vs straighten up

spring up

verb
  • To appear suddenly. 

  • To come rapidly into existence. 

straighten up

verb
  • To clarify 

  • to start living a reformed life 

  • to sit up straight, to stop hunching. 

  • to steer straight 

  • to tidy; tidy up 

  • to deal with; put in order 

  • To become straight, or straighter 

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