CHICAGO - JULY 08:  Office space is advertised for lease at the Sears Tower on July 8, 2009 in Chicago, Illinois. As companies continue to downsize more and more office space is put back on the market. The office vacancy rate in downtown Chicago is 13.7 percent, while the vacancy rate in the suburban area of the city has topped 24 percent. Nationwide the office vacancy rate has hit 15.9 percent. Getty Images logo Getty Images 4 months ago

CHICAGO - JULY 08: Office space is advertised for lease at the Sears Tower on July 8, 2009 in Chicago, Illinois. As companies continue to downsize more and more office space is put back on the market. The office vacancy rate in downtown Chicago is 13.7 percent, while the vacancy rate in the suburban area of the city has topped 24 percent. Nationwide the office vacancy rate has hit 15.9 percent.