How are you going to have a world chart to compile of the 20 most important charts in the world and not have the 2nd most important music industry country in Japan a factor in your weird point tally?
Even if Japan was counted for the top, none of their songs would be made the top 40. The chart is based on points, the first place gets 40 points, the second 39... with the exception of USA, UK, Canada, Australia and NZ (those charts receive more).
And I think this topic goes in this forum... it is not a personal chart, or what I believe, it is just a recopilation.