go up vs lessen

go up

verb
  • To forget lines or blocks during public performance. 

  • Used other than figuratively or idiomatically: see go, up. 

  • To rise or increase in price, cost, or value. 

  • To be consumed by fire. 

  • To move upwards 

  • To be built or erected 

  • To appeal for a dismissal. 

lessen

verb
  • To make less; to diminish; to reduce. 

  • To become less. 

conj
  • unless. 

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