The average age of light vehicles in operation has hit a record, increasing by two months this year to 12.2 years, as a shortage of vehicles is keeping Americans in their cars for longer, according to a study released on Monday. It’s the fifth consecutive year of increase even as the U.S. vehicle fleet recovered, growing by 3.5 million vehicles in the past year, according to the report from financial information firm S&P Global. Inc’s mobility team. The results are indicative of pent-up demand that’s likely to keep automakers, their dealers and repair shops happy for years to come. Prior to th…