bathing suit vs one-piece

bathing suit

noun
  • A tight-fitting garment worn for swimming, especially the one piece garment worn by women and girls; a swimsuit. 

one-piece

noun
  • A one-piece article of clothing, especially a swimsuit. 

adj
  • Composed of a single integral unit or so appearing. 

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