| Count | Prefix |
|---|---|
| 34 | c2- |
| 16 | c2. |
| 45 | c20 |
| 853 | c21 |
| 15 | c22 |
| 17 | c23 |
| 31 | c24 |
| 8 | c25 |
| 5 | c26 |
| 5 | c27 |
| 5 | c28 |
| 5 | c29 |
| 45 | c2a |
| 42 | c2b |
| 285 | c2c |
| 47 | c2d |
| 42 | c2e |
| 30 | c2f |
| 36 | c2g |
| 36 | c2h |
| 80 | c2i |
| 11 | c2j |
| 28 | c2k |
| 42 | c2l |
| 60 | c2m |
| 30 | c2n |
| 23 | c2o |
| 59 | c2p |
| 1 | c2q |
| 45 | c2r |
| 93 | c2s |
| 41 | c2t |
| 10 | c2u |
| 12 | c2v |
| 16 | c2w |
| 10 | c2x |
| 11 | c2y |
| 3 | c2z |