To estimate the adjusted leverage trend, use the ratio:

Net Debt / EBITDA

For each balance-sheet date, approximate:

Net Debt = interest-bearing financial liabilities − cash and cash equivalents

Use the available continuing-operations EBITDA figures:

- 2022 EBITDA: €4,913 million
- 2023 EBITDA: €1,842 million

For the 2022-01-01 balance sheet:

- Other noncurrent financial liabilities: €8,701 million
- Other current financial liabilities: €8,519 million
- Cash and cash equivalents: €7,592 million

Net debt 2022 ≈ 8,701 + 8,519 − 7,592 = €9,628 million

Net Debt / EBITDA 2022 ≈ 9,628 / 4,913 = 1.96x

For the 2023-01-01 balance sheet:

- Other noncurrent financial liabilities: €3,658 million
- Other current financial liabilities: €4,127 million
- Cash and cash equivalents: €3,919 million

Net debt 2023 ≈ 3,658 + 4,127 − 3,919 = €3,866 million

Net Debt / EBITDA 2023 ≈ 3,866 / 1,842 = 2.10x

Year-on-year change:

2.10x − 1.96x = +0.14x

Since the change is within ±0.3x, the adjusted leverage trend is Stable.

<answer>Stable</answer>