Curiosity after plummeting of performance-percentage, how is it calculated?

[Ozzy For President]

Just a question,

In a previous reply I mentioned the preformance-indicator is not as important as learning from doing the exercises and making mistakes.

I was just wondering, after going down from 99% to 78% at the moment of writing, how is it calculated?

According to the number of exercises and the correct answers it should be around 90%.

I look forward to knowing how.

Warm regrads from Mexico.
_________________
I have learnt that "sorry" is not enough; sometimes you actually have to change.
Claire London.