| Absolute elevation above sea level/inches | Year |
| 584.25 | 2031.23 |
| 644.25 | 2044.676 |
| 704.25 | 2058.122 |
| 764.25 | 2071.568 |
| 824.25 | 2085.014 |
| 884.25 | 2098.46 |
| 1124.25 | 2152.244 |