OptionaldropA line from each category's values to the category axis.
OptionalhiA line in each category from its lowest value to its highest.
OptionalspanWhether each line is drawn across a blank point (dispBlanksAs span) rather than broken at it.
OptionalupA bar in each category from the first series' value to the last's.
A line group, or a stock group, whose series are lines. Stacked series are stacked in order, the first at the bottom.