SPRINGFIELD — Gov. J.B. Pritzker announced suggested tax rates that could be used under his proposed tax structure overhaul following a state constitutional amendment.Pritzker’s proposal estimates a graduated income tax at the suggested rates would reduce the income tax burden for 97 percent of Illinois residents, while raising $3.4 billion in additional revenue for the state compared to the current structure.The Illinois Constitution currently requires a flat income tax rate. Currently it sits at 4.95 percent …