iffy vs out on a limb

iffy

adj
  • Uncertain or chancy. 

  • Of dubious authenticity, legitimacy or legality. 

out on a limb

phrase
  • In a risky, precarious, daring, or uncompromising position, especially one outside of the mainstream; vulnerable. 

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