on edge vs shaky

on edge

prep
  • Tense, nervous; consequently irritable. 

shaky

adj
  • Easily shaken; tottering; unsound. 

  • Shaking or trembling. 

  • Wavering; undecided. 

  • Full of shakes or cracks; cracked. 

  • Nervous, anxious. 

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