(diplomatic) mission vs embassy

(diplomatic) mission

embassy

noun
  • An organization or group of officials who permanently represent a sovereign state in a second sovereign state or with respect to an international organization such as the United Nations. 

  • The official residence of such a group, or of an ambassador. 

  • A temporary mission representing a sovereign state. 

  • The function or duty of an ambassador. 

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