menstruum vs rag week

menstruum

noun
  • The menses; menstrual discharge. 

  • A solvent. 

  • Any liquid medium 

rag week

noun
  • The days of the month when a woman has her period. 

  • An annual event in many universities where students engage in unusual activities to raise money for charity. 

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