legislative branch vs senate

legislative branch

noun
  • The branch of government which is concerned with the making of laws 

senate

noun
  • In some bicameral legislative systems, the upper house or chamber. 

  • A group of experienced, respected, wise individuals serving as decision makers or advisors in a political system or in institutional governance, as in a university, and traditionally of advanced age and male. 

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