Calibrate the scores of the proximity chars according to the distances.

+1      75
-1      27
+2       0
-2       0
+3       0
-3       0
+4      30
-4      48
+5      37
-5      27
+6       4
-6      35
+7       9
-7      18

Change-Id: I3c6ab06a0084c18ab595147c36c2ff4b1e961a7b