Over the past 26,000 years there have been 28 major eruptions spaced in time by between 50 and 5000 years. Three of these have caused destructive pyroclastic flows at 1800, 3550 and 9950 years ago. There is no pattern between these eruptions making it difficult to predict when the next eruption may be, but the chance of a pyroclastic flow in our time is very slim.