The wholesale price-based inflation rate jumped to 7.31 per cent in December 2009, against the Reserve Bank's forecast of 6.5 per cent-level by this fiscal end, as food items like sugar, potatoes and pulses turned costlier.Overall inflation in November had stood at 4.78 per cent. However, food inflation–covering prices of non-processed food articles – measured separately for the week ending 2nd January, eased to 17.28 per cent, from 18.22 per cent a week ago.