System Monitoring * - CPU

Thats the first time I have seen the need to make a subtraction to obtain a figure on a chart. I always thought the points were measured from X. I normally look at the top point of a colour to obtain a value. In that case grey would only be evident if there was an idle time.

I stand corrected.
Actually, I would have assumed that it was a stacked chart, hence all the components add up to 100% (rather than individually charting each component relative to the baseline)...
orange = system = 8% - 0% = 8%
blue = user = 20% - 8% = 12%
green = wait = 21% - 20% = 1%
grey = idle = 100% - 21% = 79%
TOTAL 100%

EDIT: Drat... was nicely tabulated, but it seems that extra spaces get stripped out (the final 100% is the total of the last column).
The only way to tabulate is to use code tags. The text within is automatically in fixed-pitch font, and spaces are preserved.
Col 1     Col 2
Item 1    Item 2
Of course it's a stacked chart, otherwise one element could obscure another.