Yes, unless it's been removed, there will be a small metal tag attached to one to the housing cover bolts on eh pumpkin. It will tell you the ratio.
If it's not there, the way to tell is to jack up your car, slowly turn the rear wheel one revolution while counting the revolutions your driveshaft makes. You'll need to mark the shaft to know the beginning location. It's a little tedious but it will let you know.