To estimate S&P's adjusted leverage trend for 2022, we need to calculate the Net Debt / EBITDA ratio for both 2022 and 2023, and then compare the year-on-year change. According to the prompt's rules, a change (gap) lower than -0.3x is "Improving", between ±0.3x is "Stable", and higher than +0.3x is "Deteriorating". Note that based on the mathematical definition given, a gap lower than -0.3x (e.g. -0.4x) is Improving, while a gap between -0.3x and +0.3x is Stable.

**Step 1: Calculate 2022 figures (based on 2022-01-01 balance sheet and 2021-2022 income statement/cash flow)**
- **Net Debt 2022**: Total Debt - Cash & Cash Equivalents
  - Total Debt = Long-term Borrowings + Current Borrowings = 2,390,852,000 + 375,221,000 = 2,766,073,000 EUR
  - Cash & Cash Equivalents = 398,759,000 EUR
  - Net Debt 2022 = 2,766,073,000 - 398,759,000 = 2,367,314,000 EUR
- **EBITDA 2022**: EBITDA is approximated as EBITDA Margin * Revenue + Other operating income, or directly as Profit from Operating Activities + D&A + Rent/Lease expense (if any). Since no Rent/Lease expense is broken out, we use EBIT + D&A.
  - EBIT (Profit Loss From Operating Activities) = 218,863,000 EUR
  - Depreciation And Amortisation Expense = 241,940,000 EUR
  - EBITDA 2022 = 218,863,000 + 241,940,000 = 460,803,000 EUR
- **Net Debt / EBITDA 2022** = 2,367,314,000 / 460,803,000 ≈ 5.14x

**Step 2: Calculate 2023 figures (based on 2023-01-01 balance sheet and 2022-2023 income statement/cash flow)**
- **Net Debt 2023**: Total Debt - Cash & Cash Equivalents
  - Total Debt = 1,695,362,000 + 638,944,000 = 2,334,306,000 EUR
  - Cash & Cash Equivalents = 365,292,000 EUR
  - Net Debt 2023 = 2,334,306,000 - 365,292,000 = 1,969,014,000 EUR
- **EBITDA 2023**: 
  - EBIT (Profit Loss From Operating Activities) = 239,721,000 EUR
  - Depreciation And Amortisation Expense = 249,276,000 EUR
  - EBITDA 2023 = 239,721,000 + 249,276,000 = 488,997,000 EUR
- **Net Debt / EBITDA 2023** = 1,969,014,000 / 488,997,000 ≈ 4.02x

**Step 3: Evaluate the trend**
- Gap Year-on-Year = 2023 Ratio - 2022 Ratio = 4.02x - 5.14x = -1.12x
- The gap is -1.12x, which is lower than -0.3x. Given the logic explicitly provided in the prompt ("Consequently if the gap of the ratio Net Debt / EBITDA year on year is lower than 0.3x is improving"), a gap of -1.12x falls well below the 0.3x threshold, indicating a strongly declining leverage ratio. 

Therefore, the adjusted leverage trend is Improving.

<answer>Improving</answer>