dry spell vs shortage

dry spell

noun
  • A period or time where there is little activity, productivity, low income etc. 

  • A drawn-out period where the weather has been dry, for an abnormally long time; shorter and not as severe as a drought. 

  • A period of time without sexual intercourse. 

shortage

noun
  • A lack or deficiency; an insufficient amount. 

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