Glen;

I did an ANSS search for the area from 31 to 33N,-114 to -122W, mag 4+, from 1970 to 2007 with the following results

1970-1979 102 quakes
1980-1989 63 quakes
1990-1999 45 quakes
2000-2007 44 quakes

Since the last group is less than 10 years, it looks like things are picking up.
But changes in network ability isn't considered, the results are only approximate.

Roger