(a) A tax of 7 ½% is imposed on inheritances which fall to persons other than those mentioned in sections 1 and 2 of this chapter, which, for purposes of this section, shall be described as Class III inheritances; Provided, however, That there shall be no tax imposed upon bequests to the Government of the Virgin Islands or any department or agency thereof, or to any charitable, educational or religious institution.
(b) For purposes of computing the tax on Class III inheritances, the taxable amount of such inheritances shall be determined by deducting from the total value thereof an exemption of $5,000, prorated to each person receiving a Class III inheritance in the ratio that each said inheritance bears to the total amount of all Class III inheritances.