So rents are up and the vacancy rate down.

Vacancy rate: 16.3 percent, up from 15.3 percent in the third quarter of 2009.

The vacancy rate for the whole office estate stands at just 3 per cent.

The group has maintained a vacancy rate of 3.9 per cent.

With a vacancy rate of 3 to 4 per cent, a site comes free only once every six months.