dearth vs rarity

dearth

noun
  • Scarcity; a lack or short supply. 

  • A period or condition when food is rare and hence expensive; famine. 

rarity

noun
  • A measure of the scarcity of an object. 

  • Thinness; the property of having low density 

  • A rare object. 

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