parson vs rectorial

parson

noun
  • A Roman Catholic priest of an independent parish church. 

  • A Protestant minister. 

  • An Anglican cleric having full legal control of a parish under ecclesiastical law; a rector. 

rectorial

noun
  • The events associated with the appointment of a new rector. 

adj
  • Relating to a rector. 

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