gloat vs pat oneself on the back

gloat

noun
  • An act or instance of gloating. 

verb
  • To triumph, crow, relish, glory, revel. 

  • To exhibit a conspicuous (sometimes malevolent) pleasure or sense of self-satisfaction, often at an adversary's misfortune. 

pat oneself on the back

How often have the words gloat and pat oneself on the back occurred in a corpus of books? (source: Google Ngram Viewer )