To calculate the proportion of equity to debt, we need to look at the total equity and total debt of the company. From the provided information, the total equity at the end of 2022 is 2,610 K€. The total debt is given as 601 K€.

Therefore, the proportion of equity to debt is:
Equity / Debt = 2,610 K€ / 601 K€ ≈ 4.34

So, the proportion of equity to debt is approximately 4.34.