hang up one's boots vs shelve

hang up one's boots

verb
  • retire, call it a day 

shelve

verb
  • To set aside; to quit or postpone. 

  • To place on a shelf. 

  • To furnish with shelves. 

  • To slope; to incline; to form into shelves. 

  • To have sex with. 

  • To take (drugs) by anal or vaginal insertion. 

noun
  • A rocky ledge or shelf. 

How often have the words hang up one's boots and shelve occurred in a corpus of books? (source: Google Ngram Viewer )