go up vs taper off

go up

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

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

  • To be consumed by fire. 

  • To move upwards 

  • To be built or erected 

  • To forget lines or blocks during public performance. 

  • To appeal for a dismissal. 

taper off

verb
  • To diminish or lessen gradually; to become smaller, slower, quieter, etc. 

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