preserve vs relinquish

preserve

verb
  • To protect; to keep from harm or injury. 

  • To save from decay by the use of some preservative substance, such as sugar or salt; to season and prepare (fruits, meat, etc.) for storage. 

  • To maintain throughout; to keep intact. 

noun
  • An activity with restricted access. 

  • A sweet spread made of any of a variety of fruits. 

  • A reservation, a nature preserve. 

relinquish

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

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

  • To metaphorically surrender, yield control or possession. 

  • To accept to give up, withdraw etc. 

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