urge to merge vs vehemence

urge to merge

noun
  • A strong desire to form intense emotional connections, stereotypically associated with lesbians. 

vehemence

noun
  • Eagerness, fervor, excessive strong feeling. 

  • A wild or turbulent ferocity or fury. 

  • An intense concentration, force or power. 

How often have the words urge to merge and vehemence occurred in a corpus of books? (source: Google Ngram Viewer )