One point of the over-time line: the 30 days up to a run.
The run the window ends at.
How many breaks the window holds.
The typical fall over the window, adjusted to BreakTrend.refBpm.
The middle half of the window's adjusted falls: a quarter fell less than lowBpm, a quarter more than highBpm.
lowBpm
highBpm
One point of the over-time line: the 30 days up to a run.