murky vs roky

murky

adj
  • Cloudy, indistinct, obscure. 

  • Hard to see through, as a fog or mist. 

  • Dark, dim, gloomy. 

  • Dishonest, shady. 

roky

adj
  • Misty; foggy; cloudy. 

  • Exhibiting roke (a defect in steel ingots). 

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