I don't think that any statistics of this sort is available, but the anecdotic evidence is plentiful. One of the greatest mathematicians of 20th century, Marcel Riesz, just spent his time locked in an apartment in Budapest, some friends bringing him food, and survived. Another famous mathematician, Laurent Schwatz, and his wife,
spent all the time of the war in France, with fake documents, under some
other name. (Most examples I know are about mathematicians, but this is simply because I am mostly interested in their biographies, there is nothing special about
mathematicians of course). Many Ukrainians hid Jews in their homes
(with enormous risk for themselves and their families). Of course this happened in other countries too, but I just know the situation in Ukraine better.
When I was a child (in Western Ukraine) I knew personally several Jews who survived the German occupation in Western Ukraine. (Unfortunately, they were reluctant to tell the details of their stories because of the political conditions in Soviet Union at that time. People who survived the occupation were severely discriminated. And I as a very young boy, did not apply all my abilities to extract as much as possible from their stories. Which I regret now).
There are many stories like this from countries of the former Soviet Union, Eastern Europe, and even from Germany itself. But it is hard, perhaps impossible,
to say how many people really survived the German occupation by hiding.