To determine the extent to which VINCI should rely on hybrid bonds, we evaluate the company's financial position and the market environment as of the end of 2022.

1.  **Financial Position:** VINCI exhibits a robust balance sheet with total assets of approximately €111.99 billion and equity of €29.41 billion. While it maintains a significant amount of debt (noncurrent bonds issued of €20.43 billion and short-term borrowings of €6.37 billion), its cash position is very strong, with cash and cash equivalents of €12.58 billion. The profit for the period is €4.42 billion, indicating a healthy capability to service its debt.
2.  **Market Environment:** The market data shows that the swap curve rates and bond yields rose significantly in 2022 compared to 2020 and 2021. For example, the 10Y swap curve moved from 0.053% in 2021 to 1.927% in 2022. Similarly, the iBoxx EUR Non-Financial IG yield rose from 1.298% to 2.295%. 
3.  **Capital Structure Analysis:** Hybrid bonds are typically used by companies to optimize capital structure, improve credit ratings (as they are often treated as equity by rating agencies), and manage interest rate risk. However, they carry higher coupon rates compared to senior debt. 
4.  **Conclusion:** Given VINCI’s strong cash flow, strong profitability, and its existing capital structure, there is no immediate necessity to shift heavily toward hybrid bonds. The company's current leverage is manageable, and the rising interest rate environment makes issuing new, higher-coupon hybrid debt less attractive than utilizing existing liquidity or traditional, lower-cost senior debt. Relying on a moderate amount of hybrid capital (25%) can provide the company with the benefits of equity-like treatment to maintain its credit profile while keeping interest costs lower than a more aggressive 50%+ shift. 

<answer>25%</answer>