I'll be a monkey's uncle vs amazing

I'll be a monkey's uncle

phrase
  • Often preceded by well: expressing complete surprise or disbelief. 

amazing

adj
  • Causing wonder and amazement; very surprising. 

  • Possessing uniquely wonderful qualities; very good. 

How often have the words I'll be a monkey's uncle and amazing occurred in a corpus of books? (source: Google Ngram Viewer )