The same, for bands that arrive grouped by series rather than aligned.
Totalled by the category's own value rather than by position, because a
series that skips a category leaves the arrays unaligned and pairing by
index would then divide one category's value by another's total.
The same, for bands that arrive grouped by series rather than aligned.
Totalled by the category's own value rather than by position, because a series that skips a category leaves the arrays unaligned and pairing by index would then divide one category's value by another's total.