T-shirt vs turtleneck

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. 

turtleneck

noun
  • A high, close-fitting collar, turned back on itself and covering all or most of the neck, on a sweater or similar garment. 

  • A foreskin. 

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