The CFR and LCFS are "performance-based," and allow fuel producers to calculate unique CIs for their own production pathway. Relative to a technology mandate, a fuel's performance in these programs has the potential to be more closely (but still not fully) tied to the actual CI reduction achieved by the fuel. The LCFS is credited with reducing the CI of California's transportation fuel pool by approximately 15%, and U.S. bioethanol production has increased roughly 8-fold over the past two decades to meet RFS requirements. However, cellulosic biofuel production targets set by the RFS have never been met, thus preventing the realization of the additional benefits of these fuels compared to conventional fuels (e.g., improved biodiversity in agricultural landscapes, sequestration of atmospheric carbon in soils, reduced human health externalities ).