Company ABC is required to pay their customers $20,000 after 3 years. Based on an annual effective interest rate of 4%, Andy, the company's actuary, uses full immunization strategy to construct a portfolio of assets using a 2-year zero-coupon bond and one of the following zero-coupon bonds: i. 4-year zero-coupon bond ii. 8-year zero-coupon bond Calculate the absolute difference in the par amounts for 2-year zero-coupon bond under (i) and (ii).