inquiry vs question

inquiry

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

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

question

noun
  • A sentence, phrase or word which asks for information, reply or response; an interrogative. 

  • A subject or topic for consideration or investigation. 

  • A proposal to a meeting as a topic for deliberation. 

  • A doubt or challenge about the truth, accuracy, or validity of a matter. 

verb
  • To ask a question or questions; inquire or seek to know; examine. 

  • To ask questions of; to interrogate; to ask for information. 

  • To raise doubts about; have doubts about. 

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