disburden vs disencumber

disburden

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

  • To free from a source of mental trouble. 

disencumber

verb
  • To remove an encumbrance or burden from (someone or something); unburden. 

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