damming vs emission

damming

noun
  • The installation of a dam (structure to block flow). 

emission

noun
  • The act of emitting; the act of sending forth or putting into circulation. 

  • A show; a program. 

  • Something which is emitted or sent out; issue. 

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