pinafore vs tracksuit

pinafore

noun
  • A sleeveless dress, often similar to an apron, generally worn over other clothes, and most often worn by young girls as an overdress. 

tracksuit

noun
  • A garment, usually consisting of a top and trousers (commonly known as tracksuit bottoms) worn as an outer layer by participants in sporting events such as athletics. The tracksuit is usually designed to be easily removed or replaced, before or after competing. Tracksuits have also been adopted in some cultures as leisurewear. 

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