republic vs sovereignhood

republic

noun
  • A state where sovereignty rests with the people or their representatives, rather than with a monarch or emperor; a country with no monarchy. 

  • One of the subdivisions constituting Russia. See oblast. 

sovereignhood

noun
  • The state or condition of a sovereign; sovereignty. 

  • An independent or sovereign territory. 

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