The board shall compute the average rate of general property taxation in the state by:
(a)
Adding the county, city, school district, and other general taxes, but not the special taxes on intangibles, aircraft, baled cotton or any other property which is subject to a uniform statewide tax rate, nor special assessments, and
(b)
Dividing the amount obtained by the total assessed valuation in the state as shown by the county tax rolls for the same year.
“Total assessed valuation,” as used in this section,
does not include the assessments of property which is subject to a uniform statewide tax rate.
“Special assessments,” as used in this section, mean any amount levied solely against real estate or real estate and improvements.