centuplet vs yearthousand

centuplet

noun
  • Synonym of hundred: A group of 100. 

  • One of a group of 100, particularly one of 100 babies born at the same time, from the same egg, or from the same DNA. 

yearthousand

noun
  • Meronym: yearhundred 

  • A millennium (a period of a thousand years). 

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