The range of variation has almost nothing to do with this.  Scale it however you want, and you get the same story -- the relationship between the dollar and the Yuan is essentially flat , while the relationship between the Yuan and anything else is variable and trending in one direction or another.  This proves that Chinese central bankers are pegging to the dollar first and foremost.  Sorry for the inclusion.  It's a tradeoff when trying to put too many things on one chart.