 The optimists are feeling a bit more upbeat now as we look towards North America trading, with US futures nudging higher in a more positive risk tilt - at least for the time being. Nothing is set in stone though, especially since were all waiting on the US CPI data that is to come later at 1330 GMT.Heres a look at how the SP 500 has performed in each of the last four editions of the CPI data the report covers t... 