**Step 1: Identify the industry**

REDEIA CORPORACION SA (formerly Red Eléctrica Corporación, S.A.) is the parent company of Red Eléctrica de España, the Spanish electricity transmission system operator (TSO). The company operates a regulated electricity network. Based on the provided methodologies, it fits into **Regulated Utilities**.

**Step 2: Estimate 2021 Adjusted_EBITDA**

First, compute EBITDA from the income statement:
*   Revenue (2021): 1,952,958,000 EUR
*   Other Work Capitalised (2021): 55,737,000 EUR
*   Participacion en Beneficios... (2021): 29,546,000 EUR
*   Aprovisionamientos (2021): (18,655,000) EUR
*   Other Operating Income (2021): 10,644,000 EUR
*   Employee Benefits Expense (2021): (187,341,000) EUR
*   Other Operating Expense (2021): (344,252,000) EUR
*   Imputacion de Subvenciones... (2021): 14,717,000 EUR
*   Deterioro... (2021): (730,000) EUR
EBITDA = 1,952,958 + 55,737 + 29,546 - 18,655 + 10,644 - 187,341 - 344,252 + 14,717 - 730 = 1,512,624,000 EUR.
Check: Operating Profit (2021) = 991,970,000. Depreciation & Amortisation (2021) = 522,114,000.
EBITDA = 991,970 + 522,114 = 1,514,084,000 (difference due to rounding/classifications, use sum of components: 1,512,624,000 approx, or use Op Profit + D&A = 1,514,084,000).
Using Operating Profit + D&A: 991,970 + 522,114 = 1,514,084,000 EUR.
S&P adjustments for EBITDA in Regulated Utilities: no specific adjustments detailed beyond general ones. We assume no non-recurring items to adjust, no operating leases were a separate adjustment in the data, and no JV EBITDA add-back mentioned.
Adjusted_EBITDA (2021) ≈ 1,514,084,000 EUR. (We'll use this figure).

**Step 3: Estimate 2021 FFO**

FFO = Adjusted_EBITDA - Cash Interest - Cash Taxes.
*   Cash Interest: Interest Paid Classified as Operating Activities (2021) = 121,920,000 EUR. (Interest Paid Classified as Financing Activities is 0).
*   Cash Taxes: Income Taxes Paid Refund... (2021) = 181,263,000 EUR.
FFO (2021) = 1,514,084,000 - 121,920,000 - 181,263,000 = 1,210,901,000 EUR.

**Step 4: Estimate 2021 Adjusted_Debt**

Adjusted_Debt = Total Debt + Leases + Pensions + Guarantees + Hybrid - Eligible Cash.
From Balance Sheet (2021-01-01, which is FY2021 end):
*   Long-term Borrowings: 5,896,170,000 EUR
*   Current Borrowings: 1,391,722,000 EUR
*   Total Borrowings = 7,287,892,000 EUR.
*   Cash and Cash Equivalents: 1,574,427,000 EUR.
No leases, pensions, guarantees, or hybrids are explicitly separated in the data. We'll assume they are negligible or included in the reported debt. "Noncurrent Financial Liabilities" and "Current Financial Liabilities" include derivatives and other items, but borrowings are the core debt.
Adjusted_Debt (2021) = 7,287,892,000 - 1,574,427,000 = 5,713,465,000 EUR.

**Step 5: Calculate 2021 Adjusted_Debt / Adjusted_EBITDA**

Ratio = 5,713,465,000 / 1,514,084,000 = 3.77x

**Step 6: Calculate 2021 FFO / Adjusted_Debt**

Ratio = 1,210,901,000 / 5,713,465,000 = 0.212 (21.2%)

**Step 7: Estimate 2022 Adjusted_EBITDA**

*   Revenue (2022): 2,015,036,000 EUR
*   Operating Profit (2022): 961,554,000 EUR
*   Depreciation & Amortisation (2022): 544,992,000 EUR
EBITDA = 961,554 + 544,992 = 1,506,546,000 EUR.
Adjusted_EBITDA (2022) = 1,506,546,000 EUR.

**Step 8: Estimate 2022 FFO**

*   Interest Paid (2022): 123,524,000 EUR
*   Income Taxes Paid (2022): 363,996,000 EUR
FFO (2022) = 1,506,546,000 - 123,524,000 - 363,996,000 = 1,019,026,000 EUR.

**Step 9: Estimate 2022 Adjusted_Debt**

From Balance Sheet (2022-01-01, which is FY2022 end):
*   Long-term Borrowings: 5,491,124,000 EUR
*   Current Borrowings: 721,845,000 EUR
*   Total Borrowings = 6,212,969,000 EUR.
*   Cash and Cash Equivalents: 794,824,000 EUR.
Adjusted_Debt (2022) = 6,212,969,000 - 794,824,000 = 5,418,145,000 EUR.

**Step 10: Calculate 2022 Adjusted_Debt / Adjusted_EBITDA**

Ratio = 5,418,145,000 / 1,506,546,000 = 3.60x

**Step 11: Calculate 2022 FFO / Adjusted_Debt**

Ratio = 1,019,026,000 / 5,418,145,000 = 0.188 (18.8%)

**Step 12: Classify Year-on-Year Credit Trend**

*   Leverage Change: 3.60x - 3.77x = -0.17x. 
    Thresholds: ≤ -0.2x (Improving), -0.2x to +0.2x (Stable).
    -0.17x is Stable.

*   Cash-Flow Coverage Change: 0.188 - 0.212 = -0.024 (i.e., -2.4 percentage points).
    Thresholds: ≥ +0.03 (Improving), -0.03 to +0.03 (Stable).
    -0.024 is Stable.

Both signals agree: Stable.

<answer>Stable</answer>