We don't know that.
We may have a fairly accurate count of how many tried to breach the Wall at or near Berlin.
But successful escapes perpetrated a hundred kilometers away would have been an embarrassment to the Soviets, who would have preferred to keep quiet about it.
Thus the full tally of successful escapes from East to West may remain under-counted to this day, potentially substantially so.
Let's not conflate what they did, with what they wanted to do.
Anecdotes I've read indicate rumors inside the Soviet Union of Western prosperity resulted in for example a simple pair of bluejeans being swapped even up inside the Soviet Union, for a Trabant.