centenarian vs not as young as one used to be

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. 

not as young as one used to be

How often have the words centenarian and not as young as one used to be occurred in a corpus of books? (source: Google Ngram Viewer )