Utopia National Park hosted 30,000 elephants on Friday night. The next morning, there was a 4-hour elephant exodus out of the park, at a constant rate of 2,880 elephants/hour. Over the next 7-hour period, new elephants entered the park at a constant rate. If the final number of elephants in the park was 28,980, at what rate did the new elephants enter the park?
Please reason step by step, and put your final answer within \boxed{}.
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