sternum vs top bollocks

sternum

noun
  • The breastbone, consisting of the manubrium, gladiolus, and xiphoid process. 

  • The sclerotized ventral plate of spiders, between the coxae, marking the floor of the cephalothorax. 

top bollocks

noun
  • breasts 

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