Sample Table
----------
ID  | Ref1  | Ref2
1   |  41   | 42    |
2   |  42   | 41    |
3   |  42   | 43    |
4   |  42   | 41    |
5   |  42   | 43    |
6   |  43   | 42    |
7   |  43   | 44    |
8   |  43   | 42    |
9   |  44   | 43    |
10  |  53   | 54    |
11  |  54   | 53    |
11  |  54   | 55    |
11  |  55   | 54    |
11  |  56   | 57    |
11  |  57   | 56    |

Desired Results
----------
ID  | Ref1  | Ref2  |  New Column
1   |  41   | 42    |  1
2   |  42   | 41    |  1
3   |  42   | 43    |  1
4   |  42   | 41    |  1
5   |  42   | 43    |  1
6   |  43   | 42    |  1
7   |  43   | 44    |  1
8   |  43   | 42    |  1
9   |  44   | 43    |  1
10  |  53   | 54    |  2
11  |  54   | 53    |  2
11  |  54   | 55    |  2
11  |  55   | 54    |  2
11  |  56   | 57    |  3
11  |  57   | 56    |  3