If they did not take into account state taxes, they also skipped city, township and county taxes. Sales tax can come from state, city and county, I think.
Gas taxis 18.4/gallon at the federal level, so it should be already in there, right? I am not sure. Anyway, state and city can add their own gas taxes.
Does the UK's VAT replace the income tax there or do both exist?
A more thorough report would be nice regardless of whether the U.S. is higher or lower on the chart.
A report for value obtained by those taxes would also be nice. However, that can be highly subjective.