bluestocking vs woman of letters

bluestocking

noun
  • A member of an 18th-century Blue Stockings Society. 

  • A scholarly, literary, or cultured woman. 

  • The English parliament of 1653, more commonly called the Barebones Parliament 

woman of letters

How often have the words bluestocking and woman of letters occurred in a corpus of books? (source: Google Ngram Viewer )