| Count | Prefix |
|---|---|
| 14 | xb- |
| 6 | xb. |
| 6 | xb0 |
| 12 | xb1 |
| 9 | xb2 |
| 5 | xb3 |
| 4 | xb4 |
| 3 | xb5 |
| 2 | xb6 |
| 2 | xb7 |
| 3 | xb8 |
| 2 | xb9 |
| 188 | xba |
| 27 | xbb |
| 32 | xbc |
| 21 | xbd |
| 124 | xbe |
| 10 | xbf |
| 19 | xbg |
| 26 | xbh |
| 140 | xbi |
| 15 | xbj |
| 12 | xbk |
| 102 | xbl |
| 33 | xbm |
| 23 | xbn |
| 800 | xbo |
| 19 | xbp |
| 8 | xbq |
| 135 | xbr |
| 64 | xbs |
| 44 | xbt |
| 89 | xbu |
| 4 | xbv |
| 19 | xbw |
| 28 | xbx |
| 45 | xby |
| 17 | xbz |