privative vs unproductive

privative

adj
  • consisting in the absence of something; negative 

  • causing privation; depriving 

  • indicating the absence of something 

noun
  • something that causes privation or indicates an absence 

unproductive

adj
  • Not productive; useless; fruitless. 

  • No longer used to produce new words (see examples). 

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