Ok. The original problem, im writting bachelor about forex market trade.
And geting difficult to solve which curency in pairs is strongest and witch is weakest.
EUR = xGBP = yUSD = zJPY = c
From the chart it is obviuos that GBP moved down a lot (got weaker in relation to the other currencies), but how to measure the drop in some index. And how to measure which curency's strength moved up (in realation to the oher curencies)?