| Variable | Observations | Obs. with missing data | Obs. without missing data | Minimum | Maximum | Mean | Std. deviation |
| Dia | 93 | 0 | 93 | 1.000 | 16.000 | 5.011 | 3.255 |
| Age | 93 | 0 | 93 | 5.000 | 60.000 | 29.194 | 18.212 |
| Sand | 93 | 0 | 93 | 0.000 | 1.000 | 0.946 | 0.227 |
| Clay | 93 | 0 | 93 | 0.000 | 1.000 | 0.054 | 0.227 |
| Low Traffic | 93 | 0 | 93 | 0.000 | 2.000 | 0.968 | 0.231 |
| Heavy Traffic | 93 | 0 | 93 | 0.000 | 1.000 | 0.043 | 0.204 |
| Trees | 93 | 0 | 93 | 0.000 | 1.000 | 0.903 | 0.297 |
| no trees | 93 | 0 | 93 | 0.000 | 1.000 | 0.215 | 0.413 |
| shallow unde 6 | 93 | 0 | 93 | 0.000 | 1.000 | 0.849 | 0.360 |
| deep bury | 93 | 0 | 93 | 0.000 | 1.000 | 0.032 | 0.178 |
| pressure | 93 | 0 | 93 | 55.000 | 65.000 | 55.323 | 1.616 |
| Ductile | 93 | 0 | 93 | 0.000 | 1.000 | 0.419 | 0.496 |
| GI | 93 | 0 | 93 | 0.000 | 1.000 | 0.054 | 0.227 |
| PVC | 93 | 0 | 93 | 0.000 | 1.000 | 0.247 | 0.434 |
| AC | 93 | 0 | 93 | 0.000 | 1.000 | 0.065 | 0.247 |
| HDPE | 93 | 0 | 93 | 0.000 | 5.000 | 1.075 | 2.065 |