impressive vs outstanding

impressive

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

  • Appealing. 

  • Capable of being impressed. 

outstanding

adj
  • Prominent or noticeable; standing out from others. 

  • Exceptionally good; distinguished from others by its superiority. 

  • Projecting outwards. 

  • Unresolved; not settled or finished. 

  • Owed as a debt. 

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