What is the method for determining the average time between fires?

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The method for determining the average time between fires is to gather data on the time between each fire occurrence over a particular period, such as a year or a decade. The time between adjacent fire occurrences is recorded, and the sum of the time periods is divided by the number of fires to obtain the average time between fires. For example, if there were ten fires that occurred over a period of ten years, the average time between fires would be one year.