Since the diamond is a 2D figure, then if you add time as a third dimension, you'd get a diamond-shaped cylinder. Add a blue-red spectrum color code, whereby blue is a time slice with a small surface area and red is a time slice with a large surface area, and you'd be able to plot the dangerously large Diamonds of Economic Failure over time in a way which clearly indicates when the danger signs were worst.

It not really an easy thing to do, but value weighted price/earning would probably be the most common way to do it.