How do I calculate the discount factor? Please provide the explanation with the support by proper formulas.

1. Use the February 15, 2020 U.S. Treasury quotes from the Wall Street Journal shown below to calculate the spot rate for each date given in the table. Maturity Coupon'r PriceT Discount Factor Spot Rate'r 8/15/20 2.625 100.5 2/15/21 3.625 102.0625 8/15/21 2.125 10090625 2/15/22 2.000 10109375 8/15/22 1.500 100.1875 2/15/23 2.000 101.71875 8/15/23 2.500 103.6875 2/15/24 2.750 105.125 8/15/24 2.375 104.0625 2/15/25 2.000 102.625 tCoupon and spot rate in %/year, price as percent of par