An organization's security team is analyzing historical security incident reports to help predict future events. The security incidents that have been recorded over the previous five years are as follows: 1, 2, 3, 4, and 4 incidents per year, respectively. In preparation for the upcoming year, the security analyst is tasked with estimating the frequency at which a particular security incident is expected to occur, based on the average occurrences from these figures. What is the most accurate estimate of the frequency for this incident to occur over the next year?