diminution vs downtick

diminution

noun
  • A lessening, decrease or reduction. 

  • a compositional technique where the composer shortens the melody by shortening its note values. 

  • The act or process of making diminutive. 

downtick

noun
  • A small decrease or downward change in something that has been steady or rising. 

  • A stock market transaction or quote at a price below a preceding one. 

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