The prices of gas, food and most other goods and services jumped in May, raising inflation to a new four-decade high and giving American households no respite from rising costs. Consumer prices surged 8.6% last month from 12 months earlier, faster than April’s year-over-year increase of 8.3%. The new inflation figure, the biggest yearly increase since December 1981, will heighten pressure on the Federal Reserve to continue raising interest rates aggressively. On a month-to-month basis, prices jumped 1% from April to May, fueled by prices for food, energy, rent, airline tickets and and new and used cars.