hesitate vs titubate

hesitate

verb
  • To stammer; to falter in speaking. 

  • To stop or pause respecting decision or action; to be in suspense or uncertainty as to a determination. 

  • To utter with hesitation or to intimate by a reluctant manner. 

titubate

verb
  • To stutter, stammer. 

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