| Economic Metric | Tier 1 & Tier 2 | Tier 1 Only |
|---|---|---|
| Present Value of Net Benefits at 5% discount rate over 101 years (from 2025 to 2125) | At least $82 billion | At least $10 billion |
| Return on Investment | At least 12% | At least 7% |
| Benefit-to-Cost Ratio | At least 3.90 | At least 1.40 |