disburden vs take a load off

disburden

verb
  • To free from a source of mental trouble. 

  • To rid of a burden; to free from a load carried; to unload. 

take a load off

verb
  • To go from a standing position to a sitting one. 

How often have the words disburden and take a load off occurred in a corpus of books? (source: Google Ngram Viewer )