You are a contestant in a television game where there are 20 boxes, all identically shaped and colored. There are 9 boxes containing $0, 6 boxes contain $500, and 5 boxes contain $2000. As a player you will be choosing 2 boxes, one at a time. Find the probability that you win the maximum price of $4,000, that is, both the first and the second box you choose contain $2000 each. Express the probability as a simplified fraction or round to 3 decimal places.