Roger Musson is correct in regard
to predicting small events in an area where they commonly
occur and especially in regard to your overall forecast. However,
you make it clear in your prediction that you were making
a prediction for 3 earthquake and only used to form to cover
the general area and give it in a general format. The specific
prediction for the 21st was what was evalutated. Evaluation of
the general prediction would have shown a much higher probability
of a random chance occurrence matching your forecast.
Nevertheless, your prediction for the 21st was right on target. And,
you would have been wrong in 9 out of 10 tries.