With the South Australian election just two days away, former prime minister John Howard joined the campaign trail to remind South Australians how far the state has come under Premier Steven Marshall’s leadership in the last four years. “It’s come out of the slow lane, it’s humming,” Howard told reporters in the seat of Newland, Adelaide, which is expected to be tightly contested on Saturday. The former prime minister, who was in office from 1996 to 2007 and was best known for his economic achievements, said South Australians will vote for Marshall because he’s put the state “back on the national map economically.” “The truth is that Steven Marshall has turned around South Australia’s economy,” Howard said, noting it had been in the economic slow lane under previous leaders. He cited lower unemployment rates, a Gross State Product (GSP) growth figure of 3.9 percent, and a credit rating that is …