established vs unfounded

established

adj
  • Explicitly defined, described or recognized as a reference. 

  • Of a religion, church etc.: formally recognized by a state as being official within that area. 

  • Having been in existence for a long time and therefore recognized and generally accepted. 

unfounded

adj
  • Not having been founded or instituted. 

  • Having no strong foundation; not based on solid reasons or facts. 

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