For tax exempt interest dividends, the mutual fund says that in North Carolina it is 0.68. Does it mean that I multiply exempt amount by 0.68 or 0.68% (0.0068)?

My tax exempt interest dividends is $300. If I have to multiply by 0.68 then I get 204$ as exempt in NC. Otherwise it doesn't seem right to only get exempt by $2.04? Looking for help.