You asked: what does the sample count mean
What a base rate is, and why this desk speaks in them
A base rate is a count of what has already happened in cases like this one, reported with how many cases there were — and it is the only forward-looking form of statement this desk makes.
Mayawhat these words mean
Maya reads the desk’s written explainers and the glossary. She holds no market data at all, so she can say what a thing is and cannot say what it is doing today.