hubba-hubba vs superscription

hubba-hubba

superscription

noun
  • An editorial addition at the beginning, often indicating the authorship of a piece. 

  • Something written (or engraved) on the surface, outside, or above something else; specifically, an address on a letter, envelope, etc. 

  • The act of superscribing. 

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