If NEP OpCo's adjusted available cash for any quarter falls below the base incentive amount, the IDRs will be paid using the target quarterly distribution levels below calculated using the number of NEP OpCo common units outstanding on January 26, 2017, subject to certain adjustments for repurchases, splits and combinations: During 2020, 2019 and 2018, NEP paid IDR fees of approximately $104 million, $86 million and $72 million, respectively.