motet vs national anthem

motet

noun
  • A composition adapted to sacred words in the elaborate polyphonic church style; an anthem. 

national anthem

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

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

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