boiler suit vs vestment

boiler suit

noun
  • A one-piece suit combining trousers and jacket, worn for heavy or hot manual labour. 

vestment

noun
  • Clothing. 

  • Any of the special articles of clothing worn by members of the clergy etc., especially a garment worn at the celebration of the Eucharist. 

  • A robe, gown, or other article of clothing worn as an indication of office. 

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