long in the tooth vs nonagenarian

long in the tooth

adj

  • Old; aged. 

nonagenarian

adj

  • Of or related to ninetysomethings. 

noun

  • Synonym of ninetysomething: a person between 90 and 99 years old. 

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