T-shirt vs pullover

T-shirt

noun
  • A lightweight shirt without buttons, usually with short sleeves and no collar. Often made of cotton and frequently bears a picture or slogan. 

pullover

noun
  • A sweater that must be put on by pulling it over the head; a sweater without buttons or a zipper in front 

  • An exercise performed lying on the back in which the arms are extended behind the head and exertion lifts the weight above the head. 

  • An exercise in which the gymnast pulls up from a hang lifting the legs up and over the bar thus rolling into a support position. 

  • An instance of a vehicle being pulled over. 

How often have the words T-shirt and pullover occurred in a corpus of books? (source: Google Ngram Viewer )