| Näytöt | |
| Safety and risks related to hydrogen sulfide in sewage pumping stations | 130 |
| tammikuu 2013 | helmikuu 2013 | maaliskuu 2013 | huhtikuu 2013 | toukokuu 2013 | kesäkuu 2013 | |
| Safety and risks related to hydrogen sulfide in sewage pumping stations | 30 | 20 | 19 | 37 | 21 | 3 |
| Näytöt | |
| United States of America | 74 |
| Canada | 36 |
| China | 12 |
| Finland | 3 |
| Russian Federation | 2 |
| Germany | 1 |
| France | 1 |
| Norway | 1 |
| Näytöt | |
| Toronto | 36 |
| Redwood City | 30 |
| Beijing | 8 |
| Sayreville | 8 |
| Santa Clara | 6 |
| Ashburn | 3 |
| Helsinki | 3 |
| Scranton | 3 |
| Davis | 1 |
| Mountain View | 1 |