They are very different every time a new rating comes out. With this kind of scatter I'm about to conclude their paint ratings are pretty meaningless. I say, it takes 5-10 years for them to report test results. If the paints are changing while the test is going on, by the time the test results are available you can't buy the paint that was tested. If I were choosing an exterior paint today I would pick the best paint from one of the brands listed in the table above.
Results are difficult to summarize effectively.
The best flat paint across colors was California Premium Velvet Acrylic Flat, but it doesn't adhere well to chalked paint. For low-luster, aka eggshell, Sears Best Weatherbeater Satin is pretty good overall. In semigloss Benjamin Moore MoorCraft or MoorGlo are probably best overall. The new results varied quite a bit from the '93 results. Sears Best Weatherbeater Satin came up some from '93 and Sherwin-Williams Super paint fell sharply.