Inheritance tax is imposed, pursuant to this Section and Section 3, by calculating the total inheritance tax amount (hereinafter referred to in this Section and Section 3 as the "total inheritance tax amount") for all persons who have acquired property by those causes from the decedent of a person who has acquired property by inheritance or bequest, and, on the basis of that total inheritance tax amount, in the amount calculated as the amount of inheritance tax for each person who has acquired property by those causes.