How do I create a varied width stacked 100% bar chart?

An event section represents time intervals of varying lengths. In each section, X, Y, and Z can make an appearance.

If both X and Z appear in the same event section, they'd share half the height of a column representing that section.

A stacked 100% bar chart, however, takes away all the significance from the timespan of each section, which makes it misleading for my purposes.

How can I make it so a column which represents an 80 seconds interval would be relatively 8x wider than a 10 second interval, and so on?

Hi is this what you are after?
I used the method described here:

HTML Code: