Yes! Lol, the source of the 95% was from the Stasi's own findings!
But sorry I did exaggerate. Their reports showed, along with their eyes and ears, that only 90% of the population was against them. That is why the rulers balked at sending in the troops, in 1990, to shoot those protesting against the regime. They realised that, with that number against you, the situation would quickly spiral out of control with a good chance they would all be swinging from a lamp-post.
So I do apologise for inflating the figure.