Subprime delinquencies continue to ratchet upward. But how much of that change is real? Variations in reporting styles have made that question difficult to answer, a new report by Credit Suisse First Boston suggests. In an update to its Home Equity Asset Backed Tracker index, CSFB reported a 400 basis point upswing, to 15.57 percent, in 60-day delinquencies on loans securitized between 1995 and 1999. For many vintages, the spike in delinquencies was the largest