chiefly vs in the main

chiefly

adj
  • of or relating to a chief 

adv
  • Especially or primarily; above all. 

  • Mainly or principally; almost entirely. 

in the main

prep
  • Principally; on the whole; for the most part. 

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