PUBLIC SERVICE COMPANY OF OKLAHOMA (in millions) STATEMENTS OF CASH FLOWS For the Years Ended December 31, 2020, 2019 and 2018 See Notes to Financial Statements of Registrants beginning on page 229. 214 Years Ended December 31, 2020 2019 2018 OPERATING ACTIVITIES Net Income $ 123.0  $ 137.6  $ 83.2  Adjustments to Reconcile Net Income to Net Cash Flows from Operating Activities: Depreciation and Amortization 173.5  169.5  164.0  Deferred Income Taxes 17.0  (18.2) (31.1) Allowance for Equity Funds Used During Construction (4.0) (2.7) (0.4) Mark-to-Market of Risk Management Contracts 5.5  (6.4) (3.0) Deferred Fuel Over/Under-Recovery, Net (94.0) 43.8  57.4  Change in Other Noncurrent Assets (17.9) 5.7  —  Change in Other Noncurrent Liabilities 1.6  (7.3) 21.4  Changes in Certain Components of Working Capital: Accounts Receivable, Net 1.4  15.4  5.1  Fuel, Materials and Supplies (14.1) (1.9) (2.6) Accounts Payable (29.5) 7.0  17.7  Accrued Taxes, Net 3.6  3.9  13.2  Other Current Assets 4.6  (0.7) (0.8) Other Current Liabilities (13.7) 4.6  6.4  Net Cash Flows from Operating Activities 157.0  350.3  330.5  INVESTING ACTIVITIES Construction Expenditures (337.9) (291.9) (240.2) Change in Advances to Affiliates, Net 38.8  (38.8) —  Other Investing Activities 4.0  2.6  7.2  Net Cash Flows Used for Investing Activities (295.1) (328.1) (233.0) FINANCING ACTIVITIES Issuance of Long-term Debt – Nonaffiliated —  349.5  —  Change in Advances from Affiliates, Net 155.4  (105.5) (44.1) Retirement of Long-term Debt – Nonaffiliated (13.2) (250.5) (0.5) Principal Payments for Finance Lease Obligations (3.5) (3.1) (3.3) Dividends Paid on Common Stock —  (11.3) (50.0) Other Financing Activities 0.5  (1.8) 0.8  Net Cash Flows from (Used for) Financing Activities 139.2  (22.7) (97.1) Net Increase (Decrease) in Cash and Cash Equivalents 1.1  (0.5) 0.4  Cash and Cash Equivalents at Beginning of Period 1.5  2.0  1.6  Cash and Cash Equivalents at End of Period $ 2.6  $ 1.5  $ 2.0  SUPPLEMENTARY INFORMATION Cash Paid for Interest, Net of Capitalized Amounts $ 59.1  $ 61.1  $ 62.0  Net Cash Paid (Received) for Income Taxes (11.8) 22.4  17.9  Noncash Acquisitions Under Finance Leases 3.2  5.3  4.3  Construction Expenditures Included in Current Liabilities as of December 31, 35.5  46.0  33.2  Noncash Contribution of Radial Assets from Parent 50.0  —  — 