My guess, AKK will be around 10-12%, since they are in early phase. Last year, AOK rejected the debt offer, AKK might do the same to get better bargaining power.
3 Scenarios for AKK:
1. Doing similar AOK, reject the debt offer, and issue preference share if rate is not good
2. Accept smaller debt package
3. Accept per current debt offer
GLTA. DYOR.