S&P-style FFO / net debt can be approximated from the provided IFRS data as:

**1. Estimate FFO**

A common approximation for funds from operations is:

\[
\text{FFO} \approx \text{Cash flow from operations} + \text{interest paid} - \text{working capital movements}
\]

Using the annual report cash flow components for 2022:

- Cash flows from operating activities = **€1,196m**
- Interest paid = **€202m**
- Increase/decrease in working capital excluding EEG = **€736m**
- Increase/decrease in working capital EEG = **-€1,792m**

Total working capital movement:

\[
736 - 1{,}792 = -1{,}056m
\]

Removing working capital movement from CFO:

\[
1{,}196 - (-1{,}056) = 2{,}252m
\]

Adding back interest paid:

\[
\text{FFO} \approx 2{,}252 + 202 = 2{,}454m
\]

So estimated FFO is **€2.454bn**.

**2. Estimate net debt**

Net debt is approximated as debt and lease liabilities less cash:

Debt and lease liabilities at 2022 year-end / 2023-01-01:

- Long-term borrowings = **€19,006m**
- Short-term borrowings = **€709m**
- Non-current lease liabilities = **€574m**
- Current lease liabilities = **€155m**
- Cash and cash equivalents = **€6,547m**

\[
\text{Gross debt} = 19{,}006 + 709 + 574 + 155 = 20{,}444m
\]

\[
\text{Net debt} = 20{,}444 - 6{,}547 = 13{,}897m
\]

So estimated net debt is **€13.897bn**.

**3. Calculate FFO / net debt**

\[
\frac{2{,}454}{13{,}897} = 0.1766
\]

\[
= 17.7\%
\]

<answer>17.7%</answer>