drag one's feet vs stall for time

drag one's feet

verb
  • To intentionally stall, to delay, to obstruct. 

  • To procrastinate, put off; to dawdle, avoid, or make progress slowly and reluctantly. 

stall for time

verb
  • To intentionally cause a delay; to stop; to wait. 

How often have the words drag one's feet and stall for time occurred in a corpus of books? (source: Google Ngram Viewer )