fact-finding vs indagation

fact-finding

adj
  • Designed to determine factual information; investigative. 

noun
  • The determination of factual information. 

indagation

noun
  • The determination of the condition of the genital parts at the termination of the puerperium preliminary to the discharge of the patient. 

How often have the words fact-finding and indagation occurred in a corpus of books? (source: Google Ngram Viewer )