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

First, let me identify the relevant figures:

**EBITDA (Gross Operating Income EBITDA):**
- 2022 (period 2021-01-01 to 2022-01-01): 1,428,000,000 EUR
- 2023 (period 2022-01-01 to 2023-01-01): 1,505,000,000 EUR

**Net Debt calculation:**
Net Debt = Total Debt - Cash and Cash Equivalents

I need to find total debt. From the balance sheet, debt components are:
- Other Noncurrent Financial Liabilities
- Other Current Financial Liabilities

**Debt:**
- 2022-01-01: Noncurrent financial liabilities 4,322,000,000 + Current financial liabilities 746,000,000 = 5,068,000,000 EUR
- 2023-01-01: Noncurrent financial liabilities 5,867,000,000 + Current financial liabilities 1,022,000,000 = 6,889,000,000 EUR

**Cash and Cash Equivalents:**
- 2022-01-01: 964,000,000 EUR
- 2023-01-01: 2,584,000,000 EUR

**Net Debt:**
- 2022-01-01: 5,068,000,000 - 964,000,000 = 4,104,000,000 EUR
- 2023-01-01: 6,889,000,000 - 2,584,000,000 = 4,305,000,000 EUR

**Net Debt / EBITDA:**
- 2022: 4,104,000,000 / 1,428,000,000 = 2.874x
- 2023: 4,305,000,000 / 1,505,000,000 = 2.860x

**Year-on-year change:**
Gap = 2.860 - 2.874 = -0.014x

The gap is -0.014x, which is well within the ±0.3x range for "Stable" (specifically, it's less than 0.3x in absolute value, and negative indicating slight improvement).

Wait - let me re-read the definition. "lower than 0.3x is improving" - this seems to mean if the gap is less than -0.3x (i.e., more negative than -0.3x), it's improving. But actually, re-reading: "the gap... is among ±0.3x and ±0.3x year on year" - this is Stable. "if the gap... is lower than 0.3x is improving" - I think this means if the absolute gap is less than 0.3x but negative, or if the ratio decreases by more than 0.3x?

Actually, re-reading more carefully: "Consequently if the gap of the ratio Net Debt / EBITDA year on year is lower than 0.3x is improving. If higher is Deteriorating."

I think "lower than 0.3x" means the change (2023 ratio - 2022 ratio) < -0.3x for improving, and > 0.3x for deteriorating.

My gap is -0.014x, which is between -0.3x and +0.3x, so this is **Stable**.

Actually wait - let me re-check. The definition says "among ± 0.3x and ± 0.3x" which is a bit confusing. I interpret this as: if |gap| ≤ 0.3x, it's Stable.

My gap is -0.014x, and |−0.014| = 0.014 < 0.3, so this is Stable.

<answer>Stable</answer>