isolated vs thin on the ground

isolated

adj
  • Placed or standing apart or alone; in isolation. 

  • Affecting 10 percent to 20 percent of a forecast zone. 

  • Happening or occurring only once. 

  • Such that no pawn of the same color is in an adjacent file. 

  • Which has been extracted from the organism. 

thin on the ground

adj
  • scarce, or difficult to find. 

How often have the words isolated and thin on the ground occurred in a corpus of books? (source: Google Ngram Viewer )