onesie vs snapsuit

onesie

noun
  • A one-piece garment for an infant or small child, generally worn over a diaper. 

  • One-piece fashionable streetwear worn mostly by teenagers. 

  • One-piece adult loungewear jumpsuit. 

snapsuit

noun
  • An adult garment intended to be worn with a diaper that features a snap fastener at the crotch. 

  • A baby's bodysuit with a snap fastener at the crotch. 

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