For all generation-skipping transfers occurring before January 1, 2007, there is hereby imposed a generation-skipping transfer tax upon the generation-skipping transfer or distribution of property of every resident of this state and upon the generation-skipping transfer of Nebraska real estate and tangible personal property situated in Nebraska by a nonresident. The amount of the generation-skipping transfer tax shall be the amount calculated in section 77-2101.03 reduced by the lesser of (1) the aggregate amount of all transfer taxes paid to any state or territory, the District of Columbia, or any possession of the United States in respect of any property subject to the generation-skipping transfer tax or (2) the amount determined by multiplying the amount calculated in section 77-2101.03 with respect to the taxable transfer by the percentage which the gross value of the transferred property not situated in Nebraska bears to the gross value of the transferred property.