Looks like it took about a hundred bombs to actually hit something.
I think that was quite typical of bomb placement during that era. IIRC, quite a few rocket scientists were killed and probably lots of wooden surface bldgs were scrunched by shockwave effects. But I would guess that the production facilities and work in progress were much more hardened.
Try about a thousand, or 5 thousand! The mythical accuracy of the Norden Bomb Sight was largely propaganda, within a mile was considered pretty darn good! Back in the days of dumb bombs, the shocking truth was that the massive of bombing of Germany didn't have much effect on war production at all!
What it did do was kill workers, make them homeless, or at least keep them up all night! Finally, ('44-45) by our eventual destruction of the transport infrastructure, they ran out of fuel and on the actual fronts, and ran out of fighting men. It took 5 years!