dry spell vs primary poverty

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. 

primary poverty

noun
  • The condition of living below the poverty line, having insufficient income to meet one's basic needs. 

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