knowing one’s stuff vs veteran

knowing one’s stuff

veteran

adj
  • Having had long experience, practice, or service. 

  • Of or relating to former members of the military armed forces, especially those who served during wartime. 

noun
  • A person with long experience of a particular activity. 

  • A group, animal, etc. with long experience of a particular activity. 

  • A person who has served in the armed forces, especially an old soldier who has seen long service; also called a war veteran to distinguish from veterans who weren't in armed conflict. 

How often have the words knowing one’s stuff and veteran occurred in a corpus of books? (source: Google Ngram Viewer )