To do:

In future will combine the Rahn curve and the laffer curve on one chart with Tax rate on the x-axis, Government revenue on the y-Axis and economy size on the second Y-axis.

Combined it will show the maximum tax rate for government revenue raising, and the maximum rate for prosperity.

The lower of the two should be the rate of tax is set at, unless prosperity goes up when the tax rate goes up.

Note that there are some weaknesses in this graph