impressive vs incredible

impressive

adj
  • Capable of being impressed. 

  • Appealing. 

  • Making, or tending to make, a positive impression; having power to impress 

incredible

adj
  • Amazing; astonishing; awe-inspiring. 

  • Too implausible to be credible; beyond belief; unbelievable. 

  • Marvellous; profoundly affecting; wonderful. 

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