perusal vs scrutiny

perusal

noun
  • The act of perusing; studying something carefully. 

scrutiny

noun
  • Intense study of someone or something. 

  • Thorough inspection of a situation or a case. 

  • A ticket, or little paper billet, on which a vote is written. 

  • An examination by a committee of the votes given at an election, for the purpose of correcting the poll. 

  • An examination of catechumens, in the last week of Lent, who were to receive baptism on Easter Day. 

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