enrich vs feather one's own nest

enrich

verb
  • To add nutrients or fertilizer to the soil; to fertilize. 

  • To increase the amount of one isotope in a mixture of isotopes, especially in a nuclear fuel. 

  • To adorn, ornate more richly. 

  • To make (someone or something) rich or richer. 

  • To add nutrients to foodstuffs; to fortify. 

  • To make to rise the proportion of a given constituent. 

  • To enhance. 

feather one's own nest

How often have the words enrich and feather one's own nest occurred in a corpus of books? (source: Google Ngram Viewer )