I would say it has to do with income levels of those zip codes rather than ethnicity. Temecula and Murrieta are on there too.
So is oceanside (as I suspect it would have been).

Other interesting areas

MiraMesa 92126 San Diego CA 146 19 22 187

El Cajon(?) 92115 San Diego CA 125 25 15 165

92114 (Encanto) San Diego CA 211 29 20 260
92105 (East SD) San Diego CA 143 25 19 187
92154 Otay Mesa) San Diego CA 204 25 7 236

92057 Oceanside CA 191 15 254 460
92592 Temecula CA 240 65 37 342
92563 Murrieta CA 320 105 40 465
92562 Murrieta CA 261 71 26 358