escaping vs on the run

escaping

noun
  • The act of one who escapes; an escape. 

  • That which escapes or leaks out; an emission. 

on the run

prep
  • At a disadvantage; forced to abandon a position. 

  • Constantly traveling or moving from place to place. 

  • Used other than figuratively or idiomatically: see on, run. 

  • Fleeing. 

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