debut vs early days

debut

noun
  • The first appearance of a debutante in society. 

  • The first public presentation of a theatrical play, motion picture, opera, musical composition, dance, or other performing arts piece. 

  • A performer's first performance to the public, in sport, the arts or some other area. 

  • The coming-of-age celebration of a woman's eighteenth birthday. 

verb
  • to formally introduce, as to the public 

  • to make one's initial formal appearance 

early days

noun
  • The initial period of an innovation 

  • Initial stages of a project. 

  • A time too soon to make a decision or come to a conclusion. 

How often have the words debut and early days occurred in a corpus of books? (source: Google Ngram Viewer )