After a quick google search of the image, it is obvious this is ancient. The post it comes from is dated 09-09-2012, 11:11. The same post also states that the chart itself became useless after the trading ratio rules were changed (back then the game allowed free trading, not it is limited with a 1:2, 2:1 ratio). The only use is for value comparison, and I'm not even sure that is still valid as the post is over a year old.