| Count | Prefix |
|---|---|
| 83 | obs- |
| 28 | obs. |
| 4 | obs1 |
| 4 | obs2 |
| 4 | obs3 |
| 1 | obs7 |
| 31 | obsa |
| 12 | obsb |
| 315 | obsc |
| 28 | obsd |
| 1,290 | obse |
| 5 | obsf |
| 13 | obsg |
| 41 | obsh |
| 294 | obsi |
| 14 | obsk |
| 18 | obsl |
| 9 | obsm |
| 14 | obsn |
| 125 | obso |
| 16 | obsp |
| 3 | obsq |
| 13 | obsr |
| 21 | obss |
| 304 | obst |
| 19 | obsu |
| 2 | obsv |
| 10 | obsw |
| 15 | obsy |
| 6 | obsz |