Combining Multiple IF Statements for Growth Rate Calculation

Even though I'd describe myself as an advanced Excel user, I've experienced some problems solving the following task in Excel.

I'm working on a table more or less identical to the table shown in the screenshot. The task is to calculate the growth rate for some values, e.g. earnings. However, there are some conditions that should be fulfilled while calculating the growth rate.

These are...

1. If store in both years is identical and if both earnings are positive, return growth rate (Earnings t - Earning t-1) / Earnings t-1
2. If store in both years is identical but if the denominator is zero or negativ, return "null"
3. If store in both years is identical but if numerator is zero or negativ and denominator is positive, return -100%
4. If store is not identical in both years, return "First year"
5. If store in both years is identical but if numerator or denominator is an empty cell, return "null"
6. If store in both years is identical but if numerator and denominator are 0, return 0,00%

For clarification, I've added the part of the table and the desired solutions I was referring to for the conditions.

I would be very grateful for any hint or solution to this problem...

Thank you very much in advance for your help!

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