| Count | Prefix |
|---|---|
| 9 | x-- |
| 6 | x-0 |
| 20 | x-1 |
| 14 | x-2 |
| 11 | x-3 |
| 13 | x-4 |
| 10 | x-5 |
| 6 | x-6 |
| 5 | x-7 |
| 6 | x-8 |
| 6 | x-9 |
| 178 | x-a |
| 201 | x-b |
| 367 | x-c |
| 165 | x-d |
| 122 | x-e |
| 220 | x-f |
| 132 | x-g |
| 106 | x-h |
| 143 | x-i |
| 24 | x-j |
| 39 | x-k |
| 165 | x-l |
| 273 | x-m |
| 106 | x-n |
| 109 | x-o |
| 400 | x-p |
| 20 | x-q |
| 275 | x-r |
| 407 | x-s |
| 426 | x-t |
| 27 | x-u |
| 54 | x-v |
| 115 | x-w |
| 24 | x-x |
| 25 | x-y |
| 20 | x-z |