fresh water vs sweetwater

fresh water

noun
  • Water with a very low content of dissolved salt, as opposed to brackish water or salt water. 

sweetwater

noun
  • Water that still contains sucrose after filtration by a sugar cane refinery, usually one of the main by-products of a sugar cane refining process. 

  • A variety of white grape, better known as Chasselas. 

  • neoclassical, in reference to U.S. macroeconomics and economics departments around the Great Lakes. 

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