maturity vs voting age

maturity

noun
  • The state of being mature, ready or ripe. prime state of productibility and self expression. 

  • Date when payment is due. 

  • When bodily growth has completed and/or reproduction can begin. 

  • The state of a debt obligation at the end of the term of maturation thereof, once all interest and any applicable fees have accrued to the principal. 

voting age

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