To estimate the FFO / Net Debt ratio for 2022, we need to calculate the Funds From Operations (FFO) and the Net Debt for the period ending on 2023-01-01 (which represents the end of the 2022 fiscal year).

**1. Calculate FFO (Funds From Operations)**
According to standard credit rating methodologies (like Moody's), FFO is calculated as:
FFO = Profit/Loss Attributable to Owners of Parent + Depreciation & Amortization + Impairment Losses + Non-cash items (Other adjustments) + Finance Costs (net of amounts capitalized) - Finance Income (net of amounts capitalized)

From the income statement data for 2022-01-01 to 2023-01-01:
- Profit Loss Attributable To Owners Of Parent: 1,649,000,000 EUR
- Amortizacion YPerdidas Por Deterioro De Activos: 1,532,000,000 EUR
- Other Adjustments To Reconcile Profit Loss: 1,525,000,000 EUR
- Finance Costs: 837,000,000 EUR
- Finance Income: 164,000,000 EUR

FFO = 1,649,000,000 + 1,532,000,000 + 1,525,000,000 + 837,000,000 - 164,000,000 = 5,379,000,000 EUR

**2. Calculate Net Debt**
Net Debt is calculated as Total Financial Debt minus Cash and Cash Equivalents.

Total Financial Debt (Borrowings + Lease Liabilities):
- Longterm Borrowings (2023-01-01): 12,689,000,000 EUR
- Noncurrent Lease Liabilities (2023-01-01): 1,309,000,000 EUR
- Current Borrowings And Current Portion Of Noncurrent Borrowings (2023-01-01): 2,110,000,000 EUR
- Current Lease Liabilities (2023-01-01): 177,000,000 EUR

Total Financial Debt = 12,689,000,000 + 1,309,000,000 + 2,110,000,000 + 177,000,000 = 16,285,000,000 EUR

Cash and Cash Equivalents (2023-01-01): 3,985,000,000 EUR

Net Debt = 16,285,000,000 - 3,985,000,000 = 12,300,000,000 EUR

**3. Calculate FFO / Net Debt ratio**
FFO / Net Debt = 5,379,000,000 / 12,300,000,000 ≈ 0.437317

Expressed as a ratio, this is approximately 0.44.

<answer>0.44</answer>