Step 1: Identify the relevant industry
EDP, S.A. is primarily engaged in the generation, transmission, distribution, and supply of electricity and gas. Given these activities, the relevant industry is "Regulated Utilities" (as it encompasses electricity and gas national industry and utilities), with aspects that might relate to "Unregulated Power and Gas". Following S&P's methodology for utilities, we apply the standard adjustments.

Step 2: Estimate 2021 Adjusted_EBITDA
Reported EBITDA can be reconstructed from the income statement:
EBITDA = Net Revenue + Other Income - Services Expense - Employee Benefits Expense - Other Expense - Impairment IFRS9 + Joint Ventures and Associates + Provisions
Net Revenue (Net of Revenue and Cost of Energy) 2021: 4,907,162
Other Income 2021: 1,023,988
Services Expense 2021: -888,954
Employee Benefits 2021: -666,459
Other Expense 2021: -727,965
Impairment IFRS9 2021: -32,828
Joint Ventures 2021: 108,106
Provisions 2021: 60,510
Sum = 4,907,162 + 1,023,988 - 888,954 - 666,459 - 727,965 - 32,828 + 108,106 + 60,510 = 3,783,560 EUR (thousands).
Adjustment for leases: Under S&P criteria, 75% of the lease expense is added back, and 25% is treated as interest. 2021 Lease/Right-of-use depreciation is implied as an expense within operating costs. Based on S&P lease adjustment, we add back the approximate lease component. From the cash flow statement, Payments of lease liabilities = 98,772. Assuming this is roughly the lease expense, the add-back is 75% * 98,772 ≈ 74,079.
Adjusted_EBITDA 2021 = 3,783,560 + 74,079 = 3,857,639 EUR '000.

Step 3: Estimate 2021 FFO
FFO = Adjusted_EBITDA - Cash Interest - Cash Taxes
Cash Interest 2021: Interest and similar costs of financial debt (481,329) + Interest to NCI (18,244) + Interest to related parties (0) = 499,573 EUR '000. (Note: we exclude the 25% lease interest portion from cash interest as it's already netted in EBITDA add-back).
Cash Taxes 2021: Income Tax and CESE paid = 89,845 EUR '000.
FFO 2021 = 3,857,639 - 499,573 - 89,845 = 3,268,221 EUR '000.

Step 4: Estimate 2021 Adjusted_Debt
Reported Debt 2021 = Long-term borrowings (15,299,588) + Current borrowings (1,518,348) = 16,817,936 EUR '000.
Leases 2021 = Right-of-use assets = 1,007,029 EUR '000.
Pension deficit 2021 = Noncurrent employee provisions (940,266) + Current employee provisions (179,534) = 1,119,800 EUR '000.
Other debt-like items 2021 = Other noncurrent financial liabilities (3,039,975) + Other current financial liabilities (2,781,101) + Collateral deposits (23,397 + 26,678) = 5,871,151 EUR '000.
Eligible Cash 2021 = Cash and cash equivalents = 3,222,409 EUR '000.
Adjusted_Debt 2021 = 16,817,936 + 1,007,029 + 1,119,800 + 5,871,151 - 3,222,409 = 21,593,507 EUR '000.

Step 5: Calculate 2021 Adjusted_Debt / Adjusted_EBITDA
Ratio 2021 = 21,593,507 / 3,857,639 = 5.60x.

Step 6: Calculate 2021 FFO / Adjusted_Debt
Ratio 2021 = 3,268,221 / 21,593,507 = 15.13% (0.1513).

Step 7: Estimate 2022 Adjusted_EBITDA
EBITDA 2022 components:
Net Revenue 2022: 6,121,051
Other Income 2022: 927,450
Services Expense 2022: -1,103,668
Employee Benefits 2022: -770,800
Other Expense 2022: -829,724
Impairment IFRS9 2022: -60,199
Joint Ventures 2022: 239,429
Provisions 2022: 14,539
Sum = 4,537,878 EUR '000.
Lease adjustment add-back: 75% * 133,696 (Payments of lease liabilities) ≈ 100,272.
Adjusted_EBITDA 2022 = 4,537,878 + 100,272 = 4,638,150 EUR '000.

Step 8: Estimate 2022 FFO
Cash Interest 2022 = 716,454 + 12,885 + 111 = 729,450 EUR '000.
Cash Taxes 2022 = 258,849 EUR '000.
FFO 2022 = 4,638,150 - 729,450 - 258,849 = 3,649,851 EUR '000.

Step 9: Estimate 2022 Adjusted_Debt
Reported Debt 2022 = 15,782,604 + 4,239,869 = 20,022,473 EUR '000.
Leases 2022 = 1,320,270 EUR '000.
Pension deficit 2022 = 644,299 + 126,767 = 771,066 EUR '000.
Other debt-like items 2022 = 5,159,496 + 3,600,893 + 23,765 + 29,336 = 8,813,490 EUR '000.
Eligible Cash 2022 = 4,900,205 EUR '000.
Adjusted_Debt 2022 = 20,022,473 + 1,320,270 + 771,066 + 8,813,490 - 4,900,205 = 26,027,094 EUR '000.

Step 10: Calculate 2022 Adjusted_Debt / Adjusted_EBITDA
Ratio 2022 = 26,027,094 / 4,638,150 = 5.61x.

Step 11: Calculate 2022 FFO / Adjusted_Debt
Ratio 2022 = 3,649,851 / 26,027,094 = 14.02% (0.1402).

Step 12: Classify the year-on-year credit trend
Signal 1 (Leverage): 5.61x - 5.60x = +0.01x. This is between -0.2x and +0.2x, so it is Stable.
Signal 2 (Cash-flow coverage): 0.1402 - 0.1513 = -0.0111 (or -1.11 percentage points). This is between -0.03 and +0.03, so it is Stable.
Combining the two signals: Since both signals are Stable, the credit trend is Stable.

<answer>Stable</answer>