line one's pockets vs richen

line one's pockets

verb
  • To accumulate personal wealth, especially in an illegal or morally objectionable manner. 

richen

verb
  • To make or render rich or richer. 

  • To become rich or richer; become superior in quality, condition or effectiveness. 

  • To gain richness; become heightened or intensified in brilliancy. 

How often have the words line one's pockets and richen occurred in a corpus of books? (source: Google Ngram Viewer )