Buoyed by positive same-store sales and customer traffic results, the Washington, D.C.-based National Restaurant Association’s Restaurant Performance Index (RPI) rose in November. The RPI, a monthly composite index that tracks the health of and outlook for the U.S. restaurant industry, stood at 99.9 in November, up 0.5 percent from October. However, November marked the second consecutive month in which the RPI stood below 100.