Although retail sales data reported last week surprised by not being as awful as expected, nevertheless the plunge in consumer spending since "Black September" has been dramatic.

Just how dramatic? Let's compare the cliff-diving plunge in retail sales at the end of 2008 with past retrenchments.
Below is a graph of real retail sales (i.e., adjusted for inflation) since the original, now-discontinued series was started in 1947 (in red) with the more modern version since its inception in 1990 (in blue):