To estimate the FFO (Funds From Operations) / Net Debt ratio for 2022, we must identify the relevant figures from the provided data.

1.  **Funds From Operations (FFO):**
    While "FFO" is not explicitly labeled, it is commonly approximated by the "Cash Flows From Used In Operating Activities" adjusted for non-cash items or, in a standard utility context, approximated by the Operating Cash Flow.
    *   Cash Flows From Used In Operating Activities (2022): 726,703,000 EUR.

2.  **Net Debt:**
    Net Debt is generally calculated as: (Non-current Financial Liabilities + Current Financial Liabilities) - (Cash and Cash Equivalents).
    *   **Non-current Financial Liabilities:**
        *   Other Noncurrent Financial Liabilities: 4,722,263,000 EUR.
    *   **Current Financial Liabilities:**
        *   Other Current Financial Liabilities: 619,418,000 EUR.
    *   **Cash and Cash Equivalents:**
        *   Disponibilità Liquide E Mezzi Equivalenti (2023-01-01): 559,908,000 EUR.

    Calculation of Net Debt (as of Jan 1, 2023 / End of 2022):
    *   Total Financial Liabilities = 4,722,263,000 + 619,418,000 = 5,341,681,000 EUR.
    *   Net Debt = 5,341,681,000 - 559,908,000 = 4,781,773,000 EUR.

3.  **FFO / Net Debt Ratio:**
    *   Ratio = 726,703,000 / 4,781,773,000
    *   Ratio ≈ 0.15197

(Note: The data provided for financial liabilities and cash position corresponds to the status at the start of 2023, which is the end of 2022).

<answer>0.15197</answer>