| STATE | 1993 | 1999 | 2000 |
| TBO/day | TBO/day | TBO/day | |
| Florida | 5.6 | 4.9 | 12 |
| New York | 0.3 | 0.2 | 1 |
| Pennsylvania | 2 | 1.5 | 5 |
| Virginia | 0.1 | 0.1 | ‡ |
| West Virginia | 2 | 1.5 | 4 |
| Illinois | 17.4 | 12 | 33 |
| Indiana | 2.8 | 2 | 5 |
| Kansas | 49.6 | 29 | 93 |
| Kentucky | 4.6 | 2.7 | 9 |
| Michigan | 13.8 | 7.8 | 17 |
| Missouri | 0.1 | 0.1 | 0.1 |
| Nebraska | 4.9 | 2.6 | 8 |
| North Dakota | 30.9 | 32.9 | 89 |
| Ohio | 8.3 | 6 | 16 |
| Oklahoma | 96.6 | 7.1 | 187 |
| South Dakota | 1.5 | 1.1 | 3 |
| Tennessee | 0.4 | 0.3 | 1 |
| Alabama | 18.7 | 11.1 | 29 |
| Arkansas | 10 | 7.1 | 22 |
| Louisiana | 439.8 | 12 | 303 |
| Mississippi | 22.6 | 17.9 | 55 |
| New Mexico | 68.4 | 64.4 | 179 |
| Texas | 619.1 | 449.2 | 1241 |
| Colorado | 29.4 | 18.5 | 56 |
| Montana | 17.4 | 14.9 | 39 |
| Utah | 21.8 | 16.2 | 44 |
| Wyoming | 87.7 | 61.1 | 165 |
| Alaska | 577.5 | 383.1 | 970 |
| Arizona | 0.7 | 0.7 | 2 |
| California | 293 | 273 | 742 |
| Nevada | 1.9 | 0.7 | 2 |