Standard Deviation by Manufacturer
To me, the standard deviation chart shows how accurate and how much care a company puts into making and sorting their shafts.
If your shafts have a high standard deviation or vary more than 1% weight difference, in my opinion, you need to take a look at your manufacturing process. Sorry to be harsh, but that's my opinion. We as archers don't mind paying big money for our arrows but we want high quality.