infant vs tweenie

infant

noun
  • A minor. 

  • A very young human being, from conception to somewhere between six months and two years of age after birth, needing almost constant care and attention. 

tweenie

noun
  • A child who is not quite old enough to be a teenager; a tweenager. 

  • A shot that is hit between the legs; a tweener. 

  • A 650-watt fresnel motion picture lighting instrument first manufactured by the Mole-Richardson Company. 

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