To determine the extent to which VERBUND AG should utilize hybrid bonds relative to S&P Global Ratings' equity credit cap, we first need to calculate the company's total adjusted capital. S&P defines total adjusted capital as debt plus equity. 

Using the 2022 annual report figures:
- Total Equity (2022-01-01): 6,362,949,000 EUR
- Total Liabilities (2022-01-01): Total Assets - Total Equity = 17,281,365,000 EUR - 6,362,949,000 EUR = 10,918,416,000 EUR

Total Adjusted Capital = Total Liabilities + Total Equity = 10,918,416,000 EUR + 6,362,949,000 EUR = 17,281,365,000 EUR.

Next, we calculate the maximum amount of equity credit S&P would award to hybrid bonds, which is capped at 15% of total adjusted capital:
Maximum Equity Credit = 15% × 17,281,365,000 EUR ≈ 2,592,204,750 EUR.

Now, we look at VERBUND's existing capital structure to see how much hybrid debt they already have or how their long-term debt is structured. We evaluate the noncurrent and current financial liabilities (long-term and short-term borrowings):
- Noncurrent Financial Liabilities (2022-01-01): 1,834,155,000 EUR
- Current Financial Liabilities (2022-01-01): 1,462,453,000 EUR
Total Financial Liabilities = 3,296,608,000 EUR.

VERBUND is a utility company (typically 'A' rated by S&P), and for such entities, S&P allows up to 15% of total adjusted capital in hybrid bonds to receive equity credit. The 15% cap translates to approximately 2.59 billion EUR. Given that VERBUND's total financial liabilities are around 3.3 billion EUR, the maximum 15% cap represents a substantial portion (nearly 75-80%) of their total financial debt. 

Utility companies like VERBUND, which are heavily capital-expenditure intensive, routinely optimize their capital structures by issuing hybrid bonds up to the S&P ratings agency cap. Doing so provides equity credit (supporting the credit rating) while retaining the tax deductibility of debt. Because the maximum allowable equity credit cap represents a highly relevant and attainable portion of their financial debt structure—allowing them to fully benefit from the hybrid instrument class without wasting the ratings buffer—a utility maximizing its capital efficiency should target utilizing the full capacity allowed by the rating agency.

Therefore, they should utilize hybrid bonds to the full extent of the 15% cap, which corresponds to a 100% relative utilization.

<answer>100%</answer>