I don’t have figures on how many Jews or Christians Muslims actually forced to decide between death and conversion, but my understanding is that when Muslims took over Egypt, for instance, they did not kill Christians in any sort of mass form. It took several hundred years for Egypt to gradually become more and more Islamic. (Contrast that to what happened in Spain to Jews when the Reconquista had been completed.)
Now, in India, it may have been a different story, since many Muslim invaders into India had much less respect for Buddhism and Hinduism, than they had for Judaism and Christianity. I know that the Muslims killed many hundreds, if not thousands, of Buddhists monks and destroyed Buddhist temples and libraries.
And if you look at the country with the largest Muslim population (Indonesia), you’ll find that it was Muslimized not via forced conversion, or even invasion, but by the godly example of Muslim merchants (most likely from Gujarat and other parts of Muslim India) and Muslim mystics (Sufis).