To estimate **FFO / Net debt** for 2022, use a common credit-style approximation:

**FFO ≈ Cash flows from operations before working capital movements**, after taxes and operating cash items, but excluding working-capital volatility.

From the cash-flow data:

- Cash flows from operations: **4,200.324 million**
- Working capital / regulatory-related adjustments included:
  - Decrease/increase in trade and other receivables: **405.817 million**
  - Increase/decrease in trade and other payables: **766.260 million**
  - Changes in working capital to personnel: **-142.137 million**
  - Changes in working capital for regulatory assets: **502.859 million**

Net working capital contribution:

\[
405.817 + 766.260 - 142.137 + 502.859 = 1,532.799 \text{ million}
\]

So:

\[
FFO \approx 4,200.324 - 1,532.799 = 2,667.525 \text{ million}
\]

Next, estimate **net debt** as borrowings less cash and cash equivalents:

- Long-term borrowings: **15,782.604 million**
- Current borrowings and current portion of non-current borrowings: **4,239.869 million**
- Cash and cash equivalents: **4,900.205 million**

\[
Net\ debt = 15,782.604 + 4,239.869 - 4,900.205 = 15,122.268 \text{ million}
\]

Then:

\[
FFO / Net\ debt = 2,667.525 / 15,122.268 = 0.1764
\]

As a percentage:

\[
0.1764 \times 100 = 17.64\%
\]

<answer>17.64%</answer>