consolidate vs unify

consolidate

verb
  • To combine into a single unit; to group together or join. 

  • To make stronger or more solid. 

  • With respect to debt, to pay off several debts with a single loan. 

unify

verb
  • Cause to become one; make into a unit; consolidate; merge; combine. 

  • Become one. 

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