| Density Val. | API Index | ||
| 2011 | 2006 | 2002 | |
| Very Low | 0.182 | 0.188 | 0.165 |
| Low | 0.181 | 0.174 | 0.209 |
| Medium | 0.208 | 0.207 | 0.243 |
| High | 0.224 | 0.228 | 0.235 |
| Very High | 0.208 | 0.202 | 0.150 |
| Total | 1.004 | 1.000 | 1.002 |