siren suit vs swimming costume

siren suit

noun
  • A one-piece garment for the whole body, originally designed to be put on while making one's way to an air-raid shelter. 

swimming costume

noun
  • the garments that one wears when bathing in the sea or a swimming pool, especially the one-piece garment worn by women and girls. 

How often have the words siren suit and swimming costume occurred in a corpus of books? (source: Google Ngram Viewer )