bulletproof vest vs suit of armour

bulletproof vest

noun
  • A garment worn over the torso that protects against projectiles. 

suit of armour

noun
  • A collection of garments, usually made of metal, worn over the body for protection in battle from weapons. 

How often have the words bulletproof vest and suit of armour occurred in a corpus of books? (source: Google Ngram Viewer )