Buff vs servitor

Buff

noun
  • A member of the Buffs (Royal East Kent Regiment). 

name
  • A surname. 

servitor

noun
  • One who serves in an army; a soldier. 

  • One who performs the duties of a servant. 

  • An undergraduate who performed menial duties in exchange for financial support from his college, particularly at Oxford University. 

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