double whammy vs hexing

double whammy

noun
  • A series of two events that causes adverse effects; a twofold blow or setback. 

  • A series of two events that causes positive effects; a twofold boon. 

hexing

noun
  • The act of casting a hex or curse. 

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