Usually if you're working at a high-rise, you should clean your carpet more than often. Buildings like those go through more people, and specifically go through a lot of wear and tear, especially since dust can travel floor to floor.
I'd recommend every one or two days that cleaning the office would be more ethical for business use.
Since up to 24 pounds of dirt can be tracked in by 1,000 people in a 20 day work period, it would be safe than sorry to clean almost daily.
It also depends on what type of carpet you have.
