pass on vs unbosom

pass on

verb
  • To convey or communicate. 

  • To go forward. 

  • To die. 

  • To transfer (something) to someone, especially by handing or bequeathing it to the next person in a series. 

  • To skip or decline. 

unbosom

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