monokini vs two-piece

monokini

noun
  • A one-piece swimsuit, which may cover both the chest and the crotch (as contrasted with a bikini, which consists of two pieces). 

  • The lower part of a bikini without the upper part (i.e., topless). 

two-piece

noun
  • A garment consisting of two separate parts; especially such a swimsuit 

adj
  • comprising two pieces 

How often have the words monokini and two-piece occurred in a corpus of books? (source: Google Ngram Viewer )