I am sure I have seen this before where you would make a filter selection i.e. year = 2013 then you would see the results on the graph, then you could freeze that graph and then make a new new filter selection i.e. year = 2012 and you could see both result sets on the same chart with one of them being grey so you could see the difference? Is this possible, I'm sure i seen it somewhere but cannot find this now.
