| Count | Prefix |
|---|---|
| 1,452 | us- |
| 30 | us. |
| 11 | us0 |
| 120 | us1 |
| 79 | us2 |
| 35 | us3 |
| 59 | us4 |
| 18 | us5 |
| 12 | us6 |
| 14 | us7 |
| 18 | us8 |
| 23 | us9 |
| 12,981 | usa |
| 1,737 | usb |
| 2,391 | usc |
| 1,386 | usd |
| 9,833 | use |
| 972 | usf |
| 879 | usg |
| 1,367 | ush |
| 1,382 | usi |
| 234 | usj |
| 299 | usk |
| 859 | usl |
| 1,499 | usm |
| 617 | usn |
| 685 | uso |
| 1,902 | usp |
| 78 | usq |
| 805 | usr |
| 2,315 | uss |
| 2,034 | ust |
| 464 | usu |
| 522 | usv |
| 678 | usw |
| 61 | usx |
| 129 | usy |
| 69 | usz |