On March 1, 1993, Elwood deposited $4,200 into a bank account. The account credited interest at a nominal interest rate of 4% per year, compounded quarterly, when the balance was under $5,000. The account credited interest at a nominal interest rate of 6% per year, compounded semiannually, when the balance was at least $5,000. Elwood withdrew $1,000 on March 1, 1999. If there were no other deposits or withdrawals, determine Elwood's account balance on March 1, 2003. (Assume that interest accrues continuously, not just at the end of a compounding period.)