Your uncle has $400,000 invested at 6.5%, and he now wants to retire. He wants to withdraw $30,000 at the beginning of each year, beginning immediately. He also wants to have $21,000.00 left to give his kids when he ceases to withdraw funds from the account. For how many years can he make the $30,000 withdrawals and still have $21,000.00 left in the end?