Wisconsin-based Marten Transport experienced the highest net income in its history last year, finishing 2012 with a 12.3-percent year-over-year rise in income to $27.3 million. Net income in the fourth quarter beat the company’s previous record for a quarter of $7.663 million by $56,000. Operating revenue from truckload and logistics operations rose by $30 million year over year to $638.5 million in 2012. Minus fuel surcharge revenue, operating expenses as a percentag...