... but these types of graphs are always misleading when they have multiple Y-axis values. The blue wave should be a tenth of the size of the green wave, or it should have pirates riding on it or something.
QFT.
"Graphs" are (or were, originally) intended to offer a visual representation that makes a quick and clear demonstration of a data set. The real purpose of graphs has long since been co-opted by both the gummint and the media. This graph is one example, where two lines are superimposed but the Y axis of one is exaggerated by a factor of ten relative to the other. Meaning that the visual representation of the line (which IS the graph) does not present a true snapshot of the data.
A couple of days ago the news sites were showing a "graph" purporting to show the DOW Jones average spiking to new highs. The line was almost vertical, and it looked VERY impressive. Except that the lowest value on the Y axis was not zero, it was 14,000, and the peak was 14,500. If the graph actually went to zero, it wouldn't have been nearly as impressive.
I can't find that one, but here's an example, showing all of 2012 up to present. Looks pretty impressive, until you realize it starts at 12,000. Recast that same line on a graph with a Y axis that starts at zero and it won't look nearly as impressive.
http://finance.yahoo.com/echarts?s=^DJI+Interactive#symbol=^dji;range=1y;compare=;indicator=volume;charttype=area;crosshair=on;ohlcvalues=0;logscale=off;source=undefined;