cojoin vs congregate

cojoin

verb
  • To join together; to conjoin. 

congregate

verb
  • To come together; to assemble; to meet. 

  • To collect into an assembly or assemblage; to bring into one place, or into a united body. 

adj
  • Collective; assembled; compact. 

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