A tax research group says Maine’s ranking for its business tax climate has improved to 30th nationally. The Tax Foundation’s 2013 list shows an improvement from Maine’s number 37 for taxation that affect business: corporate, individual income and sales taxes, unemployment insurance taxes and taxes on property. Governor Paul LePage pointed out that Maine had the biggest improvement in the foundation’s ranking this year, a result of the repeal of Maine’s alternative minimum tax and a change in treatment of net operating losses.