elderdom vs predominancy

elderdom

noun
  • Preeminence; superiority. 

  • The role or influence of an elder or elders. 

  • The authority, rule, or office of an elder. 

  • The state of being an elder, or of being older; elderhood. 

  • Authority; dominion. 

predominancy

noun
  • Predominance. 

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