ISLAMABAD: Short-term inflation, measured by the Sensitive Price Index (SPI), surged by 15.16 per cent year on year in the week ending May 7, driven largely by higher retail prices of petroleum products and eatables, according to official data released on Friday. The increase in SPI was a broad-based cost shock, reflecting persistent cost-of-living pressures. This was mainly driven by the sharpest annual increases in petrol (58.3pc), diesel (55.8pc), electricity charges (52.6pc), wheat flour (50.7pc) and LPG (48.8pc).