MP vs senator

MP

noun
  • Member of Parliament 

  • Megapixel 

  • Machine Pistol 

  • Military Police; military policeman 

  • mana points or magic points 

senator

noun
  • A member, normally elected, in the house or chamber of a legislature called a senate, as, for instance, the legislatures of the United States and Canada. 

  • A member of the ruler’s council or governing council in general, a leading statesman. 

  • A member of the ancient Roman Senate. 

  • A member of a governing council in other states in the ancient world. 

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