optimum vs untopped

optimum

adj
  • The best or most advantageous; surpassing all others. 

noun
  • The best or most favorable condition, or the greatest amount or degree possible under specific sets of comparable circumstances. 

untopped

adj
  • Unsurpassed. 

  • Not having had the top cut off. 

  • Not covered with a topping. 

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