I suppose an interesting calculation would be, the total number baptised in the last twenty years ,minus the death rate of 1%, and we should have a figure that we can add to the 3.5 million of twenty years ago, and see how many really are "missing".
In my head I say roughly 6 million baptised, 1 million dead, leaves a nett increase of 5 million. Which should mean they now number 8.5 million.
So where are the missing million ? Just my guess, but real figures would be revealing.
Love
Wobble