adulthood vs sexual maturity

adulthood

noun
  • The state or condition of a human being once it has reached physical maturity, and is presumed to have reached a state of psychological maturity, to wit: once it has become an adult. 

  • The time period of a human being's majority; the time during which a human being has reached physical maturity, and ending with its death. 

sexual maturity

noun
  • The stage when an organism can reproduce, though this is dissimilar from adulthood. 

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