Every chart below is drawn by an ordinary corechart class with draw
options that change what it means. The adapter never receives those
options, so each one names its reading with an explicit
chartType. Click on a chart and use the arrow keys to
explore it through audio, text, and braille.
Pitch carries the retention between stages, not the raw count.
Pitch carries the size of a cohort; the announcement names its side.
Pitch carries each step's contribution; the running total travels with it.