foe vs preserver

foe

noun

  • An enemy. 

  • A unit of energy equal to 10⁴⁴ joules. 

preserver

noun

  • A person who prepares preserves of fruit or preserved meats. 

  • A person who refinishes furniture. 

  • One who preserves. 

  • A life preserver. 

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