When you say the "warmers won't produce any graphs covering the same periods", I think you are wrong. They do. Here's an example. http://www.whrc.org/resource

When you say the "warmers won't produce any graphs covering the same periods", I think you are wrong. They do. Here's an example. http://www.whrc.org/resources/primer_fundamentals.html http://www.whrc.org/resources/primer_fundamentals.html