difficulty vs reliance

difficulty

noun
  • Physical danger from the environment, especially with risk of drowning 

  • An obstacle that hinders achievement of a goal. 

  • The state of being difficult, or hard to do. 

  • An objection. 

  • An awkward situation or quarrel. 

  • That which cannot be easily understood or believed. 

reliance

noun
  • A person or thing which relies on another. 

  • The condition of being reliant or dependent. 

  • The act of relying (on or in someone or something); trust. 

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