centenarian vs octogenarian

centenarian

noun
  • One who or that which is at least 100 years old. 

adj
  • Aged 100 years or more; extremely old. 

  • Of or relating to centenarians or a centenary celebration. 

octogenarian

noun
  • Synonym of eightysomething: a person between 80 and 89 years old. 

adj
  • Of or related to eightysomethings. 

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