Demarcus earned $$12,000$ from his summer job. He plans to leave the money in a $4$ percent certificate of deposit $($CD$)$ for three years, but his banker has asked Demarcus whether he wants the interest earned on the CD mailed to him at the end of each year or reinvested in the CD$.$ Approximately how much more will Demarcus earn if he decides to reinvest the interest rather than withdraw the interest income each year?