.02;

When you compute an average such as number of quakes per day, there may be no real day with that value. If there are 365 quakes in a given year, you might say that's one per day. But those quakes may have happened in one week or been spread around in any number of ways. The average of one per day assumes a uniform distribution, literally one every day.

That's the beauty of the Jones method. By sorting into the desired windows and counting windows with quakes vs total windows you get a valid probability no matter how they are distributed.

Roger