I have checked your data using our in-house version of the PDE
catalog which contains monthly data through July, 2000 only, as
such my numbers will differ slightly from yours.

For events in the 9-10 degree band I get:

202 total events (all magnitudes)
139 windows contain 202 events
Total number of 10-day windows: 387
Probability a window will contain an event: 139/387 = 0.359

However, significant increase in activity is expected, so
we also need to look at higher magnitude bands.

For events in the 9-10 degree band with M>4.5 (any magnitude)

86 total events
71 windows contain 86 events
Total Number of 10-day windows: 387
Probability a window will contain an event of M>=4.5 =71/387 = 0.183

For events in the 9-10 degree band with M>5.0 (any magnitude)

33 total events
28 windows contain 33 events
Total Number of 10-day windows: 387
Probability a window will contain an event of M>=5.0 =28/387 = 0.0723

This is a good test to see if our programs are doing the same
thing Roger. Keep posting your results.