derivable vs on tap

derivable

adj
  • able to be derived, deducible 

on tap

prep
  • Available directly from the barrel by way of a tap. 

  • Readily available; ready for use in whatever quantity is desired. 

  • On an agenda, planned, expected. 

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