Charlotte Office Rents

For four years and counting, the office average rent seems to be level. Why wouldn't the average rent change as economic conditions have changed?

This graph doesn't show the vacancy rate. Office building  development is a complex business. It would be my guess that the consistency of the average rent is a direct result of:

1. No new office buildings are being built
2. The vacancy rate is probably at a normal level and thus owners do not have to lower rates to attract leasees.
3. New businesses are being created and office space utilized but not at a robust rate. It seems to me the number of companies going out of business are being replaced by new businesses.
4. Rents will dramatically increase as the economy improves. Simply because of  the time it takes to bring an office building online from vacant land. A strong office space demand with a finite office space availability will drive rents higher.
5. Financing for an office building must be almost non-existent.
Prediction - as the economy improves the average rent for office space will dramatically increase.