To estimate the FFO / Net Debt ratio for TenneT Holding B.V. for 2022, we first calculate the Funds From Operations (FFO) and the Net Debt using the provided financial data.

**1. Calculate Funds From Operations (FFO):**
TenneT's FFO is determined by taking the Profit Before Tax and adjusting for non-cash items, followed by deducting taxes paid. 
- **Profit Before Tax:** -1,233,000,000 EUR
- **Adjustments for non-cash items and other operating activities:**
  - Depreciation and Amortisation: 1,233,000,000 EUR
  - Losses on disposal of non-current assets: 38,000,000 EUR
  - Adjustments for undistributed profits of investments: 120,000,000 EUR
  - Dividends received classified as operating: 92,000,000 EUR
  - Adjustments for provisions: 104,000,000 EUR
  - Other adjustments for non-cash items: 1,347,000,000 EUR

Subtotal (Operating cash flow before working capital changes and taxes) = -1,233 + 1,233 + 38 + 120 + 92 + 104 + 1,347 = 1,701,000,000 EUR.

- **Income Taxes Paid:** 231,000,000 EUR
**FFO** = 1,701,000,000 - 231,000,000 = **1,470,000,000 EUR**

**2. Calculate Net Debt:**
Net Debt is calculated as total interest-bearing borrowings (including lease liabilities) minus cash and cash equivalents. 
- Long-term borrowings: 19,006,000,000 EUR
- Short-term borrowings: 709,000,000 EUR
- Non-current lease liabilities: 574,000,000 EUR
- Current lease liabilities: 155,000,000 EUR
- Total Debt = 19,006 + 709 + 574 + 155 = 20,444,000,000 EUR
- Cash and Cash Equivalents: 6,547,000,000 EUR

**Net Debt** = 20,444,000,000 - 6,547,000,000 = **13,897,000,000 EUR**

**3. FFO / Net Debt Ratio:**
Ratio = 1,470,000,000 / 13,897,000,000 ≈ 0.10577 (or 10.6%)

<answer>0.106</answer>