priority vs substantial

priority

noun
  • An item's relative importance. 

  • A goal of a person or an organisation. 

  • A superior claim to use by virtue of being validly published at an earlier date. 

  • The quality of being earlier or coming first compared to another thing; the state of being prior. 

  • right of way; The right to pass (an intersection) before other road users 

substantial

noun
  • Anything having substance; an essential part. 

adj
  • Most important; essential. 

  • Not imaginary; real; actual; true; veritable. 

  • Having a substance; actually existing. 

  • Corporeal; material; firm. 

  • Possessed of goods or an estate; moderately wealthy. 

  • Satisfying; having sufficient substance to be nourishing or filling. 

  • Large in size, quantity, or value; ample; significant. 

  • Having good substance; strong; stout; solid; firm. 

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