To estimate S&P's credit trend for Fortum Oyj from 2021 to 2022, we analyze the provided financial data following S&P's general corporate methodology and the principles for Unregulated Power and Gas/Regulated Utilities. 

**Step 1: Identify the Relevant Industry**
Fortum Oyj operates in the power and gas sector, which falls under S&P's Unregulated Power and Gas / Regulated Utilities methodologies. We will apply the standard analytical adjustments suited for this sector.

**Step 2: Estimate the 2021 Adjusted EBITDA**
S&P adjusts reported EBITDA by removing items affecting comparability (e.g., capital gains/losses on divestments, mark-to-market variations, and impairment charges). Fortum’s "Comparable EBITDA" excludes these non-operating and non-cash items, making it an excellent proxy for S&P’s Adjusted EBITDA. 
- Adjusted EBITDA = Comparable EBITDA = **2,016,000,000 EUR**

**Step 3: Estimate the 2021 Funds From Operations (FFO)**
- Cash Interest Paid = 147,000,000 EUR
- Cash Taxes Paid = 279,000,000 EUR
- FFO = 2,016,000,000 - 147,000,000 - 279,000,000 = **1,590,000,000 EUR**

**Step 4: Estimate the 2021 Adjusted Debt**
We include short-term and long-term financial liabilities, along with significant debt-like liabilities like unfunded pensions. We then subtract highly liquid cash.
- Other Noncurrent Financial Liabilities: 8,701,000,000 EUR
- Other Current Financial Liabilities: 8,519,000,000 EUR
- Pension Deficit (Noncurrent Recognised Liabilities Defined Benefit Plan): 1,190,000,000 EUR
- Liquid Funds (Cash): 7,592,000,000 EUR
- *Note: Nuclear provisions and dedicated nuclear funds offset each other closely (3,891m provision minus 3,515m fund).*
- Adjusted Debt = (8,701,000,000 + 8,519,000,000 + 1,190,000,000) - 7,592,000,000 = **10,818,000,000 EUR**

**Step 5: Calculate 2021 Adjusted Debt / Adjusted EBITDA**
- 10,818,000,000 / 2,016,000,000 = **5.37x**

**Step 6: Calculate 2021 FFO / Adjusted Debt**
- 1,590,000,000 / 10,818,000,000 = **0.147 (14.7%)**

**Step 7: Estimate the 2022 Adjusted EBITDA**
- Adjusted EBITDA = Comparable EBITDA = **2,436,000,000 EUR**

**Step 8: Estimate the 2022 Funds From Operations (FFO)**
- Cash Interest Paid = 201,000,000 EUR
- Cash Taxes Paid = 167,000,000 EUR
- FFO = 2,436,000,000 - 201,000,000 - 167,000,000 = **2,068,000,000 EUR**

**Step 9: Estimate the 2022 Adjusted Debt**
Following Fortum's major restructuring and deconsolidation of Uniper, their liabilities shrunk considerably.
- Other Noncurrent Financial Liabilities: 3,658,000,000 EUR
- Other Current Financial Liabilities: 4,127,000,000 EUR
- Pension Deficit: 13,000,000 EUR
- Liquid Funds (Cash): 3,919,000,000 EUR
- Adjusted Debt = (3,658,000,000 + 4,127,000,000 + 13,000,000) - 3,919,000,000 = **3,879,000,000 EUR**

**Step 10: Calculate 2022 Adjusted Debt / Adjusted EBITDA**
- 3,879,000,000 / 2,436,000,000 = **1.59x**

**Step 11: Calculate 2022 FFO / Adjusted Debt**
- 2,068,000,000 / 3,879,000,000 = **0.533 (53.3%)**

**Step 12: Trend Classification**
- **Leverage signal:** The ratio changed from 5.37x to 1.59x, a decrease of 3.78x (≤ -0.2x), pointing solidly towards an **Improving** trend.
- **Cash flow coverage signal:** FFO/Debt changed from 0.147 to 0.533, an increase of 0.386 (≥ +0.03), indicating an **Improving** trend.

Both signals strongly agree due to material deleveraging and robust EBITDA generation from continuing operations.

<answer>Improving</answer>