The Brötchen Mystery

We Europeans pride ourselves on our omnipresent bakeries supplying fresh and good bread. But sometimes, this supply is cut off.

As a hard working CS student, I rarely visit a supermarket or bakery before 7 pm. By this time, all the good kinds of bread and Brötchen (aka. "Semmeli") are usually gone. However, plenty of people are still hovering around the remaining (and inferior) bread types, figuring out how to compromise.

Surely, these stores must have statistics about their average consumption, broken up by kind of bread. If anyone would care to look at these numbers, I'm sure they could optimize the types of bread they should produce. Which would leave me with fresh Brötchen, even at 7 pm.