| Valeur | Catégorie | le cas | |
|---|---|---|---|
| 1 | By sewers | 137 |
0.2%
|
| 2 | Protected canal | 447 |
0.5%
|
| 3 | Opened canal | 426 |
0.5%
|
| 4 | Swallow-hole | 124 |
0.2%
|
| 5 | River | 26 |
0%
|
| 6 | Hole | 6688 |
8.1%
|
| 7 | Nature | 50372 |
61.4%
|
| 8 | In the yard | 9714 |
11.8%
|
| 9 | In the street | 14141 |
17.2%
|
| 96 | Other | 17 |
0%
|
| 99 | 3 |
0%
|