incumbent on vs paramount

incumbent on

paramount

adj
  • Highest, supreme; also, chief, leading, pre-eminent. 

  • Of the highest importance. 

noun
  • A chief or superior; (specifically, chiefly South Africa) an African chief having the highest status in a region; a paramount chief. 

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