To calculate the FFO / Net Debt ratio for NATURGY ENERGY GROUP SA for the year 2022, we first need to determine the Funds From Operations (FFO) and the Net Debt.

**1. Funds From Operations (FFO)**
The standard methodology (used by rating agencies like S&P) for calculating FFO is to take the Cash Flow from Operating Activities and reverse the cash impact of changes in working capital. 

* Cash Flows From Operating Activities: 4,242,000,000 EUR
* Increase/Decrease In Working Capital (Cash effect): -272,000,000 EUR 

Since the working capital change represents a cash outflow of 272 million EUR, we add it back to find the cash generated before working capital requirements:
FFO = Cash Flows From Operating Activities - Changes in Working Capital
FFO = 4,242,000,000 - (-272,000,000) = 4,514,000,000 EUR

**2. Net Debt**
Net Debt is calculated as Total Financial Liabilities (both current and non-current, which inherently includes borrowings and lease liabilities) minus Cash and Cash Equivalents.

* Noncurrent Financial Liabilities: 13,999,000,000 EUR
* Current Financial Liabilities: 2,302,000,000 EUR
* Cash And Cash Equivalents: 3,985,000,000 EUR

Total Financial Debt = 13,999,000,000 + 2,302,000,000 = 16,301,000,000 EUR
Net Debt = 16,301,000,000 - 3,985,000,000 = 12,316,000,000 EUR

**3. FFO / Net Debt Ratio**
Ratio = FFO / Net Debt
Ratio = 4,514,000,000 / 12,316,000,000 ≈ 0.3665

<answer>0.3665</answer>