shudder vs tremble

shudder

verb
  • To vibrate jerkily. 

  • To shake nervously, often from fear or horror. 

noun
  • A moment of almost pleasurable fear; a frisson. 

  • A shivering tremor, often from fear or horror. 

tremble

verb
  • To shake, quiver, or vibrate. 

  • To fear; to be afraid. 

noun
  • A shake, quiver, or vibration. 

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