posterior vs rusty dusty

posterior

noun
  • The hinder parts of the body. 

  • The probability that a hypothesis is true (calculated by Bayes' theorem). 

adj
  • Following in order or in time. 

  • Next to, or facing the main stem or axis. 

  • Relating to or denoting presentation of a fetus in which the rear or caudal end is nearest the cervix and emerges first at birth. 

rusty dusty

noun
  • The buttocks of someone who sits and does nothing. 

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