If the federal government imposes a federal documentary stamp tax on real estate transfers at the same rate as, or a higher rate than, that imposed by this chapter, this chapter shall cease to have any force and effect; but if such federal tax is imposed at a rate less than that imposed by this chapter, this chapter shall continue in effect but the tax imposed by this chapter shall be reduced by the amount of such federal tax.
(1967, P.A. 693, S. 11.)