PX vs BSpec pace at every track

Every event the class ran, at any track, oldest to newest on the chart and newest first in the table. Each point is the class's best lap as a share of PX's best on the same day: the weather and the day cancel out, so one figure compares across years where lap times cannot; a class that suits one track more than another still reads differently there. It still moves when the yardstick's own balance changes or its field thins, and an event the yardstick did not run has no point. A best from fewer than three cars is greyed. The rule changes that took effect between two events are folded between their rows.