The data used for this report is extracted from CNSS Earthquake Catalog using the following search criteria for deep quakes.
catalog=CNSS
start_time=19xx/01/01,00:00:00
end_time=20xx/12/31,23:59:59
minimum_magnitude=3.0
maximum_magnitude=9
minimum_depth=500
maximum_depth=700
event_type=E
Deep quakes seem to be stabilizing, after a peak of 600 per year in 1998.
Offered by Kiko.