firmness vs shyness

firmness

noun
  • security; steadfastness; good grip 

  • strictness; mental strength 

  • physical durability; rigidness (of material) 

shyness

noun
  • The quality of being shy; a fear of social interactions. 

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