Bachelor of Arts vs Master of Science

Bachelor of Arts

noun
  • A collegiate degree, usually involving three to four years of study (about 120 semester hours) in liberal arts. 

Master of Science

noun
  • A degree that usually requires 2-3 years beyond a Bachelor of Science and emphasizes science and scientific applications. The degree is less advanced than a Doctorate degree. 

How often have the words Bachelor of Arts and Master of Science occurred in a corpus of books? (source: Google Ngram Viewer )