codex vs playbook

codex

noun
  • An early manuscript book. 

  • An official list of medicines and medicinal ingredients. 

  • A book bound in the modern manner, by joining pages, as opposed to a rolled scroll. 

playbook

noun
  • A book containing the text of a play or plays. 

  • A set of commonly employed tactics and strategies. 

  • A book of games and amusements for children. 

  • A book of strategies (plays) for use in American football (and by extension other sports or disciplines). 

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