Based on the price action in the foreign exchange market this morning, FX traders are starting to become immune to weaker U.S. data. Nearly every U.S. economic report released over the past month has been distorted by the brutal winter weather. Temperatures will rise eventually and economic data will normalize but we still have at least another month worth of softer economic data ahead.The news that manufacturing activity in the Philadelphia region contracted at its fastest pace in 12 months se…