Notes:
1) Stacked data cannot have any negative values. I don't think i have ever seen a
stacked bar chart with negative values just as a side observation.
---->There has been one request for this though...
This method should do a single pass through the data set and calculate all needed values,
such as: min, max, sum, etc... so that we can do this in one pass through the data.
Rather than once for each.