firman vs ukase

firman

noun
  • A royal decree issued by a sovereign in certain historical Islamic states, especially by the Sultan of Turkey. 

ukase

noun
  • An authoritative proclamation; an edict, especially decreed by a Russian czar or (later) emperor. 

  • Any absolutist order or arrogant proclamation 

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