Interestingly, while historians have made estimates, the Jehovah's Witnesses likely know the exact figures but choose not to share them.
The exact figures of what, how many “resisted”? You are trying to put an exact number something that is impossible to put an exact number on. Someone who spoke against the regime, went to jail, renounced their faith in custody, was released, later regretted that decision and rejoined. Did they resist, or not? People who broke down under torture and gave up names of their fellow believers. Did they resist, or not? People who reasoned it was proper to lie on forms to fool the Nazis and got released from prison that way. Did they resist or not? Someone who was a JW for social or family reasons but decided it wasn’t worth it when the Nazis came to power. Is that counted as a failure of JWs to resist? People who were true believers but simply couldn’t withstand the terror, or who compromised to save themselves, or their children, or others. Children who were removed from parents and were indoctrinated by the regime. All these scenarios, and many more complicated situations played out countless times. I don’t think we are in a position to judge except to say that any act of resistance was remarkable in the circumstances. We don’t need exact numbers to make the obvious observation that JWs stood out massively. We don’t need an exact figure in order to draw the same moral conclusion as the United States Holocaust Memorial Museum that JWs were an “island of spiritual resistance” and that other churches have had to come to terms with the “widespread complicity” of their leadership and ordinary members.