JG’s chart shows about a 20% decline from the peak in the median price of detached homes (if you smooth out or ignore the fluctuations).
Your April 2007 number is the mean not the median.
Edit – Additional Note: The April 2007 median for SFR for LaJolla was 1.5 Mil for 38 sales. Data quick separates into Single-family and condominums, not explicitly detached vs attached, but implied.