persistence vs pig-headedness

persistence

noun
  • Continuation of the previous day's weather (particularly temperature and precipitation statistics). 

  • The number of times an operation can be iteratively applied to a number before it reaches a permanently constant state. 

  • The property of being persistent. 

  • Of data, the property of continuing to exist after the termination of the program. 

pig-headedness

How often have the words persistence and pig-headedness occurred in a corpus of books? (source: Google Ngram Viewer )