Index | B1 | B2 | B3 | B4 |
B1 | 1 | 1/3 | 1/2 | 2 |
B2 | 3 | 1 | 2 | 4 |
B3 | 2 | 1/2 | 1 | 2 |
B4 | 1/2 | 1/4 | 1/2 | 1 |