hymn vs national anthem

hymn

noun
  • A song of praise or worship, especially a religious one. 

verb
  • To praise or extol in hymns. 

  • To sing a hymn. 

national anthem

noun
  • The official song of a constituent state of a country. 

  • The official song of a nation or sovereign state, generally of a patriotic nature and played at events to celebrate or honor said state. 

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