To estimate the S&P adjusted leverage trend, we need to calculate the Net Debt / EBITDA ratio for the years ending 2022 (data as of 2022-01-01) and 2023 (data as of 2023-01-01). Note that in financial reporting contexts provided here, the label "2022-01-01" typically refers to the balance sheet at the beginning of the period or the end of the previous fiscal year (FY2021), while the income statement flows are for the period ending 2022-01-01 (FY2021) or 2023-01-01 (FY2022). However, standard annual report data usually presents the current year-end balance sheet and the current year income statement. Let's align the data based on the periods provided:

**Period 1: Year ended 2022-01-01 (FY2021)**
*   **EBITDA:** The fact `"Gross Operating Income EBITDA" 2021-01-01 - 2022-01-01` is **1,428,000,000 EUR**.
*   **Net Debt Calculation:**
    *   Total Financial Liabilities are not explicitly summed as a single "Total Debt" line, but we can derive Net Debt from Cash and Financial Liabilities.
    *   Cash and Cash Equivalents (2022-01-01): **964,000,000 EUR**.
    *   Financial Liabilities:
        *   Other Noncurrent Financial Liabilities (2022-01-01): **4,322,000,000 EUR**.
        *   Other Current Financial Liabilities (2022-01-01): **746,000,000 EUR**.
        *   Total Gross Debt = 4,322 + 746 = **5,068,000,000 EUR**.
    *   Net Debt = Gross Debt - Cash = 5,068 - 964 = **4,104,000,000 EUR**.
*   **Leverage Ratio (2021):** Net Debt / EBITDA = 4,104 / 1,428 ≈ **2.87x**.

**Period 2: Year ended 2023-01-01 (FY2022)**
*   **EBITDA:** The fact `"Gross Operating Income EBITDA" 2022-01-01 - 2023-01-01` is **1,505,000,000 EUR**.
*   **Net Debt Calculation:**
    *   Cash and Cash Equivalents (2023-01-01): **2,584,000,000 EUR**.
    *   Financial Liabilities:
        *   Other Noncurrent Financial Liabilities (2023-01-01): **5,867,000,000 EUR**.
        *   Other Current Financial Liabilities (2023-01-01): **1,022,000,000 EUR**.
        *   Total Gross Debt = 5,867 + 1,022 = **6,889,000,000 EUR**.
    *   Net Debt = Gross Debt - Cash = 6,889 - 2,584 = **4,305,000,000 EUR**.
*   **Leverage Ratio (2022):** Net Debt / EBITDA = 4,305 / 1,505 ≈ **2.86x**.

**Trend Analysis:**
*   Leverage 2021: 2.87x
*   Leverage 2022: 2.86x
*   Change (Gap): 2.86 - 2.87 = **-0.01x**.

The definition states:
*   **Stable**: Gap is among ± 0.3x (i.e., between -0.3x and +0.3x).
*   **Improving**: Gap is lower than -0.3x (significant decrease in leverage). *Correction on prompt interpretation*: The prompt says "if the gap ... is lower than 0.3x is improving". This phrasing is slightly ambiguous. Usually, "lower leverage" is improving. Let's re-read 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."
    *   Standard financial logic: A decrease in leverage is improving. An increase is deteriorating.
    *   Prompt logic check: "Gap ... is among ± 0.3x ... Stable". This implies a band of stability.
    *   "If the gap ... is lower than 0.3x is improving". This likely means if the *change* represents a significant reduction (negative gap beyond the stable band) or simply if the resulting ratio is lower? No, it refers to the gap.
    *   Let's look at the bounds. If the gap is -0.01, it is within the range [-0.3, 0.3].
    *   Therefore, it falls under the **Stable** definition.

Let's double check the "Improving" condition. If the prompt meant "If the ratio decreases by more than 0.3x", the gap would be < -0.3. If it meant "If the ratio is lower", that contradicts the "gap" terminology. Given the "Stable" definition explicitly covers the ±0.3x range, and our gap is -0.01x, it is firmly inside the stable range.

<answer>Stable</answer>