blood clot vs coagulum

blood clot

noun
  • A clot formed from platelets and other elements; that forms in a blood vessel in a living organism, and causes thrombosis or obstruction of the vessel at its point of formation or travel to other areas of the body. 

coagulum

noun
  • A mass of coagulated material; a clot or curd 

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