property values

Metropolitan Regional Information Systems, Inc. as of 22 January, 2010.  Here's the report on some real estate in Washington, DC.
                                           total tax value       Land              Buildings  
1600 Pa Ave, N.W. '07     $193,926 M   $115,200 M    $ 97,306 M
                                        '08       $381,850 M   $284,544 M    $ 97,306 M
                                        '09       $398,926 M   $298,771 M    $100,225 M    
The observation is that the land increased in value by a factor of 247% in the year between 2007 and 2008.  I wonder what might have happened between the year 2007 and 2008 that would make the value of the White House rise so amazingly in the eyes of the DC tax assessor?

We have heard that property values are decreasing all across the country.  However, the tax assessors in Washington must know something we don't.  These statistics indicate a tremendous rise in tax value has occurred.  I wonder what might have happened between the year 2007 and 2008 that would make the value of the White House rise so amazingly?  It can't be for the tax revenue, as government buildings and property are exempt from paying taxes.

Pressing on...

Now, the year the White House was built is noted as 1840.  If my history serves me correctly, the British military torched the President's house at this address.  At the time it was grey.  After the British left, the house was rebuilt and painted white, thus the title The White House.  Here are some other statistics, culled from a History of the White House on the internet:
•There are 132 rooms, 35 bathrooms, and 6 levels in the Residence. There are also 412 doors, 147 windows, 28 fireplaces, 8 staircases, and 3 elevators.


•At various times in history, the White House has been known as the "President's Palace," the "President's House," and the "Executive Mansion." President Theodore Roosevelt officially gave the White House its current name in 1901.
•Presidential Firsts while in office... President James Polk (1845-49) was the first President to have his photograph taken... President Theodore Roosevelt (1901-09) was not only the first President to ride in an automobile, but also the first President to travel outside the country when he visited Panama... President Franklin Roosevelt (1933-45) was the first President to ride in an airplane.
•With five full-time chefs, the White House kitchen is able to serve dinner to as many as 140 guests and hors d'oeuvres to more than 1,000.
•The White House requires 570 gallons of paint to cover its outside surface.
•For recreation, the White House has a variety of facilities available to its residents, including a tennis court, jogging track, swimming pool, movie theater, and bowling lane.

I wonder if the assessors actually went inside to make their adjustment in value?