one of a kind vs pioneering

one of a kind

noun
  • A unique specimen. 

pioneering

adj
  • Involving accomplishments or activities that have not been done before, or developing or using new methods or techniques. 

noun
  • A scoutcraft skill that involves building structures using staves and knots. 

  • The activity of the verb pioneer. 

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