acumen vs shrewdness

acumen

noun
  • Quickness of perception or discernment; penetration of mind; the faculty of nice discrimination. 

  • A bony, often sharp, protuberance, especially that of the ischium. 

  • A sharp, tapering point extending from a plant. 

shrewdness

noun
  • The quality of being shrewd. 

  • An invented collective name for a group of apes. 

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