fluidity vs unpredictability

fluidity

noun
  • The quality of being fluid or free-flowing 

  • A measure of the extent to which something is fluid. The reciprocal of its viscosity. 

  • The state of being fluid rather than viscous 

unpredictability

noun
  • The quality of being unpredictable. 

  • Something which is unpredictable. 

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