inquiry vs trial run

inquiry

noun
  • Search for truth, information, or knowledge; examination of facts or principles; research; investigation 

  • The act of inquiring; a seeking of information by asking questions; interrogation; a question or questioning. 

trial run

noun
  • An empirical test of the suitability or effectiveness of a method or thing by running it at least once. 

  • An empirical test of the suitability or capability of a person or actor by letting him perform at least once. 

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