its difficult to get precise measurements of ride hight. Even though your on flat ground, unless its really flat, like the smooth floor of a garage or shop, its hard to get accurate measurements.

I'd go by the feel of the car more than the hight. If your shock is blown, you'll feel the car bouncing more, and you'll notice that wheel hopping over potholes, bumps, rr tracks, rather than smoothly moving up then down.