choose vs gradate

choose

verb
  • To pick; to make the choice of; to select. 

  • To elect. 

  • To prefer; to wish; to desire. 

  • To decide to act in a certain way. 

conj
  • The binomial coefficient of the previous and following number. 

gradate

verb
  • To arrange in order of grades. 

  • To change imperceptibly from one gradation of tone etc. to another. 

  • To bring to a certain strength or grade of concentration. 

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