go bananas vs vent one's spleen

go bananas

verb
  • To get angry; to go mad. 

  • To become silly or excited; to go crazy. 

vent one's spleen

verb
  • To openly express pent-up anger, often on an unrelated matter or person. 

How often have the words go bananas and vent one's spleen occurred in a corpus of books? (source: Google Ngram Viewer )