The company is a regulated utility with stable cash flows, but it carries a high level of debt (≈ 73 % of capital) and a net‑debt/EBITDA ratio of about 5.4. Interest coverage is comfortable (≈ 11×), but the current leverage limits the capacity to issue additional senior debt without risking a rating downgrade. Hybrid bonds can be treated as equity‑like by rating agencies, providing a way to raise capital without diluting equity and to support the large investment programme (intangible assets grew by ≈ 1 bn in 2022). However, hybrid financing carries a yield premium (likely 4.5‑5.5 % in the current rate environment), and excessive reliance would increase financial expense and subordination risk. A moderate proportion of hybrid bonds – roughly one‑quarter of total debt – would give the company the equity‑like benefits while keeping cost and risk manageable. This aligns with typical capital‑structure targets for regulated utilities.

<answer>25%</answer>