bit part vs leading man

bit part

noun
  • A minor role, generally not assigned a name. 

leading man

noun
  • A man who does or can play the lead role in a movie, play or other production; a person who frequently plays such roles. 

  • The type of conventionally handsome and approachable man who is perceived as being capable of playing male lead roles in movies or other productions. 

How often have the words bit part and leading man occurred in a corpus of books? (source: Google Ngram Viewer )