I need to calculate the Net Debt / EBITDA ratio for 2022 and 2023 to determine the trend.

First, let me identify the relevant data from the annual report.

**For 2022 (period 2021-01-01 to 2022-01-01):**
- Cash And Cash Equivalents: 10,518,700,000 EUR
- Bank Overdrafts And Other Cash Position Items: 241,900,000 EUR
- Current Financial Liabilities Excluding Concession Liabilities: 8,624,300,000 EUR
- Noncurrent Financial Liabilities Excluding Concession Liabilities: 10,462,500,000 EUR

**For 2023 (period 2022-01-01 to 2023-01-01):**
- Cash And Cash Equivalents: 9,012,200,000 EUR
- Bank Overdrafts And Other Cash Position Items: 213,600,000 EUR
- Current Financial Liabilities Excluding Concession Liabilities: 6,521,400,000 EUR
- Noncurrent Financial Liabilities Excluding Concession Liabilities: 19,692,100,000 EUR

**Net Debt Calculation:**

Net Debt = Total Financial Debt - Cash and Cash Equivalents

For 2022:
- Total Financial Debt = 8,624,300,000 + 10,462,500,000 = 19,086,800,000 EUR
- Cash = 10,518,700,000 EUR
- Net Debt = 19,086,800,000 - 10,518,700,000 = 8,568,100,000 EUR

For 2023:
- Total Financial Debt = 6,521,400,000 + 19,692,100,000 = 26,213,500,000 EUR
- Cash = 9,012,200,000 EUR
- Net Debt = 26,213,500,000 - 9,012,200,000 = 17,201,300,000 EUR

**EBITDA Calculation:**

I need to find EBITDA. From the cash flow statement, I can use:
"Cash Flows From Used In Operations Before Changes In Working Capital" which is approximately EBITDA - working capital changes, but let me look for a better proxy.

Actually, let me use Operating Income and add back depreciation:
- Operating Income Before Share Of Net Income Loss Of Equity Accounted Entities 2022: 1,212,700,000 EUR
- Operating Depreciation Amortization Provisions And Impairment Losses 2022: 2,117,200,000 EUR

EBITDA 2022 = 1,212,700,000 + 2,117,200,000 = 3,329,900,000 EUR

For 2023:
- Operating Income Before Share Of Net Income Loss Of Equity Accounted Entities 2023: 2,206,300,000 EUR
- Operating Depreciation Amortization Provisions And Impairment Losses 2023: 3,178,600,000 EUR

EBITDA 2023 = 2,206,300,000 + 3,178,600,000 = 5,384,900,000 EUR

**Net Debt / EBITDA Ratios:**

For 2022: 8,568,100,000 / 3,329,900,000 = 2.57x

For 2023: 17,201,300,000 / 5,384,900,000 = 3.19x

**Change in ratio:**
3.19 - 2.57 = 0.62x

Since the gap is 0.62x, which is greater than 0.3x, and the ratio increased (deteriorated), this indicates **Deteriorating**.

Let me double-check my EBITDA calculation. Actually, I should verify if "Cash Flows From Used In Operations Before Changes In Working Capital" is a better proxy for EBITDA.

For 2022: 3,213,200,000 EUR
For 2023: 4,804,300,000 EUR

Using this as EBITDA proxy:
2022: 8,568,100,000 / 3,213,200,000 = 2.67x
2023: 17,201,300,000 / 4,804,300,000 = 3.58x

Gap: 3.58 - 2.67 = 0.91x

Either way, the gap exceeds 0.3x and the ratio is increasing.

Actually, let me reconsider. S&P typically uses "Funds From Operations" or similar. But with the data given, let me use a more standard approach.

Looking at this again - the massive increase in goodwill (from 6.2B to 11.6B) and property plant and equipment suggests a major acquisition (likely Suez). This would increase debt significantly.

The Net Debt / EBITDA ratio is clearly increasing significantly, well beyond the 0.3x threshold for "Stable."

<answer>Deteriorating</answer>