Read this and answer the question. If the question is unanswerable, say "unanswerable".

In 2006, the Houston metropolitan area ranked first in Texas and third in the U.S. within the Category of "Best Places for Business and Careers" by Forbes magazine. Foreign governments have established 92 consular offices in Houston's metropolitan area, the third highest in the nation. Forty foreign governments maintain trade and commercial offices here and 23 active foreign chambers of commerce and trade associations. Twenty-five foreign banks representing 13 nations operate in Houston, providing financial assistance to the international community.

Houston ranked 23rd in which category by Forbes magazine in 2006?
unanswerable