pack up vs regrade

pack up

verb
  • To put back together. 

  • To clear away and place into storage. 

  • To break, to cease to function. 

  • To give in. 

  • To move one’s residence. 

  • To prepare for shipping, as a gift. 

  • To put into bags to prepare to move. 

regrade

verb
  • To regroup or reassign. 

  • To change the classification of (potentially secret documentation). 

  • To grade again, give a new grade or grading to. 

noun
  • The act or process of grading again. 

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