boyo vs sweet sixteen

boyo

noun
  • A boy or lad. 

  • A stereotypically Welsh form of address for a man, usually younger than the speaker. 

sweet sixteen

noun
  • sixteen 

  • A girl's sixteenth birthday, or sixteenth-birthday party and a related coming of age party. 

How often have the words boyo and sweet sixteen occurred in a corpus of books? (source: Google Ngram Viewer )