hang up one's boots vs relinquish

hang up one's boots

verb
  • retire, call it a day 

relinquish

verb
  • To give up, abandon or retire from something. To trade away. 

  • To let go (free, away), physically release. 

  • To metaphorically surrender, yield control or possession. 

  • To accept to give up, withdraw etc. 

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