autochthonic vs indigenous

autochthonic

adj
  • existing where it was formed or born; native, aboriginal, indigenous 

indigenous

adj
  • Born or originating in, native to a land or region, especially before an intrusion. 

  • Innate, inborn. 

  • In particular, of or relating to a people (or their language or culture) that inhabited a region prior to the arrival of people of other cultures which became dominant (e.g., through colonialism), and which maintains a distinct culture. 

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