covert vs sanctuary

covert

noun
  • A hiding place. 

  • A covering. 

  • A disguise. 

  • A feather that covers the bases of flight feathers. 

  • Area of thick undergrowth where animals hide. 

adj
  • Under coverture. 

  • Secret, surreptitious, concealed. 

sanctuary

noun
  • A place of safety, refuge, or protection. 

  • A state of being protected, asylum. 

  • The consecrated (or sacred) area of a church or temple around its tabernacle or altar. 

  • My car is a sanctuary, where none can disturb me except for people who cut me off. 

  • An area set aside for protection. 

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