T-shirt vs singlet

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. 

singlet

noun
  • A person who does not have a form of multiplicity, i.e. a single persona occupying one human body. 

  • A multiplet having a single member, especially a single spectroscopic peak. 

  • A quantum state having zero spin. 

  • A one-piece, tight-fitting uniform, usually made of spandex or nylon, required in wrestling and powerlifting. 

  • A sleeveless buttonless shirt with a low-cut neck. 

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