coadjuvant vs concerted

coadjuvant

adj
  • cooperating 

noun
  • An adjuvant. 

concerted

adj
  • Performed through a concert of effort; done by agreement or in combination. 

  • Having separate parts for voices and instruments. 

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