We compute total adjusted capital (debt plus equity) for 2023. Debt consists of long‑term borrowings (1,695,362 k€) plus current borrowings (638,944 k€), giving 2,334,306 k€. Equity is 1,517,534 k€. Therefore total adjusted capital = 2,334,306 k€ + 1,517,534 k€ = 3,851,840 k€. The S&P cap limits equity credit on hybrids to 15% of total adjusted capital, i.e., 0.15 × 3,851,840 k€ ≈ 577,776 k€. The company currently has no hybrid debt, so it can issue hybrids up to this limit. To make full use of the allowed equity credit, the appropriate level is 100 % of the cap.

<answer>100%</answer>