A rural library district may impose a regular property tax levy in an amount equal to that which would be produced by a levy of fifty cents per thousand dollars of assessed value multiplied by an assessed valuation equal to one hundred percent of the true and fair value of the taxable property in the rural library district, as determined by the department of revenue's indicated county ratio: PROVIDED, That when any county assessor shall find that the aggregate rate of levy on any property will exceed the limitation set forth in RCW
84.52.043 and
84.52.050, as now or hereafter amended, before recomputing and establishing a consolidated levy in the manner set forth in RCW
84.52.010, the assessor shall first reduce the levy of any rural library district, by such amount as may be necessary, but the levy of any rural library district shall not be reduced to less than fifty cents per thousand dollars against the value of the taxable property, as determined by the county, prior to any further adjustments pursuant to RCW
84.52.010. For purposes of this section "regular property tax levy" shall mean a levy subject to the limitations provided for in Article VII, section 2 of the state Constitution and/or by statute.