changing vs unsteady

changing

noun
  • Change; alteration. 

unsteady

adj
  • Inconstant in purpose, or volatile in behavior. 

  • Lacking regularity or uniformity. 

  • Not held firmly in position, physically unstable. 

verb
  • To render unsteady, removing balance. 

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