Well here's a partial explanation for the Q1 slump in 90278...

90260 is Lawndale. It is directly east of north Redondo Beach, across Inglewood Blvd. In recent years it has been transformed into a Redondo Beach wannabe. But parts of it are very slummy. Property values have risen through the roof, probably because desperate buyers so badly want something more "affordable" that they will bid up slums or the better properties next to the slums. Q1 2006 was particularly strong in Lawndale. Maybe that's where the fickle buyers of Redondo have been going.