@levampyre yeah, I'm sorry to dampen your enthusiasm!
Let's say this: for a more precise calculation, groceries only count as things you buy.
They're only "organic", "biological" or "ecological" if they are labelled as such.
And let's say the percentage is by price, not volume or count or weight. So if you buy one Bio apple that's 8€ and 2 bags of conventionally-grown kidney beans at 1€ apiece, that's 80% of your groceries that are organic.
Do those parameters help?