extensive vs unfenced

extensive

adj
  • Having a great extent; covering a large area; vast. 

  • Serving to extend or lengthen; characterized by extension. 

  • Having a combined system entropy that equals the sum of the entropies of the independent systems. 

  • Considerable in amount. 

unfenced

adj
  • Not enclosed by a fence or other boundary; free to roam over a wider area. 

  • Without protection; defenseless. 

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