Your question is extremely vague. What does it mean being in "agreement" and "when they started taking over"?
An answer to that extremely vague question could be given simply by how many voted for them in the different elections where they tried to elect some candidates. In 1933, they received about 44% of the vote, far from any other party. Those votes were not evenly distributed everywhere in Germany, but the NSDAP party was definitely a major political force everywhere and a prevalent one almost everywhere, with a few exceptions mainly in big cities, in Bavaria and the Ruhr. One can easily argue that they had already "started taking over" Germany by that time, however.
We can also argue that a few of the 12% non-registered voters "were in agreement" with the nazis, but it's almost impossible to say to which extent. The same goes with the reactionaries, and centrists, that could "agree" to an extent, enough to make concessions, or even ally with the NSDAP on some issues, but not enough to vote for them, or give them full reign, in what we would call a strategic vote in today's language.
Another point to make is that the NSDAP was a populist party, that appealed to the masses with a vocabulary that was there to inflame passions, to find culprits and push easy solutions to complex problems. It's really easy to be convinced by such a rhetoric, without "agreeing" to everything that the party planned to do, or what they will actually do once in power. It would be unfair to think that every single person that voted for the NSDAP in 1933 had the hindsight and the political, economical and intellectual background necessary to grasp the extent of the derive that was about to happen.
Let's not forget, finally, that the political climate was plagued by intimidation and violence and that the democratic exercise of 1933 could easily be regarded as a tainted one by contemporary standards, moreover by modern ones, so even if they seem telling, those numbers need to be taken with a grain of salt by any metrics.