"One of the significant findings, which we saw in our second quarter report also, was that overall vacancy continued to creep up," Faith Ramsour, director of research for Cushman of Illinois, tells GlobeSt.com. "Overall vacancy is 11.4%, which is the highest ever recorded. We hit a high last quarter as well and it's only continued to creep up."

According to Cushman's numbers, available inventory has hit 130 million square feet, but Ramsour makes the interesting distinction that the notable increase has been entirely in the amount of direct space available on the market. "When you're looking at vacancy, the sublease vacancy rate has remained consistent," Ramsour says. "It's right now 0.6 percent, and it's been in that range since mid-2000, so when we look at the overall vacancy rate, we're looking at an increase in space available on a direct basis. It's also the sixth straight quarter of negative absorption, meaning more vacant space came on the market than was leased to users."

According to Grubb & Ellis' stats, Q3 saw around 774,000 square feet of negative absorption. This brings net absorption year to date to nearly 3.8 million square feet, Grubb's research says. As a corollary to the increased vacancy and decrease demand, average asking rental rates have also taking a hit, dropping to $4.76 per square foot, according to Grubb's data.