cleric vs sky pilot

cleric

noun
  • A member of the clergy. 

  • A spellcaster class that receives their spells (especially healing) from their deity. 

adj
  • Of or pertaining to the clergy. 

sky pilot

noun
  • A clergyman, especially a military chaplain or padre. 

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