gladden vs pluck up

gladden

verb
  • To cause (something) to become more glad. 

pluck up

verb
  • To become more cheerful. 

  • To remove or acquire by plucking from, for example, the ground; to pick up. 

  • To summon positive emotion (especially courage); to muster. 

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