I would have to say it is more nuanced than this table makes it.
PA for example, sales tax is 6% across the state, and two specific small areas add surcharges, so an average is not overly helpful.
You also pay state income tax on 401k/IRA contributions when made, since we don't tax retirement income. So if you are doing traditional to Roth conversions in PA, you would be able to reduce that state taxable amount by the amount you've already paid tax on (and I *believe* you can do all contributions first, so you wouldn't be paying tax on conversions until you ran through all your original contributions and hit your gains. Don't quote me on this yet as it is not very common here).