Fortum’s reported data show negative equity in some years and large liabilities, with significant discontinued operations losses in 2022 and substantial cash flow pressures. The 2022 balance sheet shows Equity Attributable To Owners Of Parent of 7,670,000,00 EUR and Noncontrolling Interests 67,000,000 EUR, with Liabilities of 15,905,000,000 EUR, and Total Assets 23,642,000,000 EUR. The large negative comprehensive income from discontinued operations and high losses reduce equity, suggesting a need for higher planning buffers. However, the data do not explicitly indicate reliance on hybrid (convertible or non-embedded equity) instruments in the reported capital structure. Given the scale of liabilities and the dips in equity, a cautious approach would favor moderate to partial use of hybrids to bolster core equity without unduly diluting existing shareholders. Therefore, a mid-range level like 50% seems reasonable as a balance between maintaining solvency and avoiding excessive equity-like dilution. Final answer: 50% XML line below. 
<answer>50%</answer>