The ratio of cooper pairs and normal electrons in superconducting state

Is there a certain ratio between cooper pairs and normal electrons above which the sample can be said to be in a superconducting state? According to the Ginzburg-Landau theory the sample is in a superconducting state when the order parameter is above zero, but this is hard to realize in practise. Is there more developed model to define the superconducting state? Thank you for your answers!