decoct vs phase down

decoct

verb
  • To reduce or diminish. 

  • To heat as if by boiling. 

  • To make an infusion. 

  • To digest in the stomach. 

  • To devise. 

  • To reduce, or concentrate by boiling down. 

phase down

verb
  • To gradually reduce the size or scale of 

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