S&P-style FFO / Net debt can be approximated as:

- **FFO** ≈ Cash flow from operations before working-capital movements  
- **Net debt** ≈ Total financial debt including lease liabilities and hybrid instruments treated as debt, less cash and cash equivalents

Using the data provided:

**1. Estimate FFO**

Start from operating cash flow:

- Cash flows from operating activities = **€10,443m**

Remove working-capital effects:
- Decrease/increase in trade and other receivables = **-€1,701m**
- Decrease/increase in inventories = **+€521m**
- Increase/decrease in trade and other payables = **+€44m**

Net working-capital effect:

\[
-1{,}701 + 521 + 44 = -1{,}136 \text{m}
\]

So, operating cash flow before working-capital movements:

\[
10{,}443 - (-1{,}136) = 11{,}579 \text{m}
\]

Estimated **FFO = €11,579m**.

**2. Estimate net debt**

Financial debt components at 2022 year-end / 2023-01-01:

Noncurrent:
- Debt with credit institutions and bonds = **€36,129m**
- Capital instruments with financial liability characteristics = **€576m**
- Noncurrent lease liabilities = **€2,287m**
- Other noncurrent financial liabilities = **€1,534m**

Current:
- Current debt with credit institutions and bonds = **€10,458m**
- Current capital instruments with financial liability characteristics = **€87m**
- Current lease liabilities = **€151m**
- Other current financial liabilities = **€5,058m**

Gross debt estimate:

\[
36{,}129 + 576 + 2{,}287 + 1{,}534 + 10{,}458 + 87 + 151 + 5{,}058 = 56{,}280 \text{m}
\]

Less cash and cash equivalents:

- Cash = **€4,608m**

Net debt:

\[
56{,}280 - 4{,}608 = 51{,}672 \text{m}
\]

**3. FFO / Net debt**

\[
\frac{11{,}579}{51{,}672} = 0.2241
\]

So the estimated **FFO / Net debt ratio for 2022 is approximately 22.4%**.

<answer>22.4%</answer>