about device instance enumeration

Question

I’ve got a problem. That is, when we use those Windows APIs,such as SetupDiGetClassDevs() and SetupDiEnumDeviceInterfaces(), to enumerate all the instances of the usb device class, what I wanna make sure are the answers to these questions:Is there a certain rule which determines the order of being enumerated among all the instances? In other words,If we can depend on a certain rule to foreknow which device instance will be enumerated first,which will be the next and which will be the last? If there is,then what it is? If not,how can we let the first attached one be first enumerated,the next will be next,and the last will be last?