dependence vs enslavement

dependence

noun
  • The state of being dependent, of relying upon another. 

  • An irresistible physical or psychological need, especially for a chemical substance. 

enslavement

noun
  • The act of enslaving or the state of being a slave; bondage 

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