footbag vs treasure chest

footbag

noun
  • A small beanbag or sandbag used as a ball in a number of sports and games. It is typically controlled by the feet, but in some sports every part of the body except the hands and arms may be used. 

  • Any of the sports that use the footbag. 

treasure chest

noun
  • Any source of something valuable or beautiful. 

  • A treasury, especially a state or royal treasury. 

  • A chest filled with treasure, especially one used by pirates, etc. 

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