perseverate vs push on

perseverate

verb
  • To persist in doing something; to continue to repeat an action after the original stimulus has ended. 

  • To cause the perseveration of (a given reflex or response). 

push on

verb
  • To persist; persevere. 

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

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