Options:Speed:Connection Speed
Set speed to Cable/DSL (or less).

Options:Uploads:Basic:Upload Bandwidth
Set slider so upload speed is about 12 KB/s. The connection speed needs to be Cable/DSL or less so that way you can set a speed low enough to what you want.

In general throttling upload bandwidth may help you avoid being called a bandwidth hog by your ISP. It also makes it easier to have some idea of how much bandwidth you use in a month if you have a per month usage cap.