There is lot of difference between the studies by different organizations. The company which got first rank in one study will not get rank any where close to that rank by other organization. (may be some companies don't participate in all stidies). But participated company shold get some what close ranking in alll studies. If not there is fundamental doubt in these stidies. It does not make any sense one getting 1st rank in one study and no where near to that rank in another study. Some time I get doubt are these manipulated studies or real studies
