hypercriticize vs pick at

hypercriticize

verb
  • To criticize with unjust severity. 

pick at

verb
  • To pick on or repeatedly criticize (someone). 

  • To touch, grab, handle, or pull tentatively or gingerly, using a utensil or one's fingers. 

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