Spartan vs plucky

Spartan

noun
  • A citizen of Sparta; a native or inhabitant of Sparta. 

  • A red apple cultivar from British Columbia, Canada 

adj
  • Of or relating to Sparta or its citizens. 

plucky

adj
  • Having or showing pluck, courage or spirit in trying circumstances. 

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