A WT magazine was printed on this subject last summer. They blame the increase mainly on mentally unbalanced ones. Then they go on to say that they don't know nor do they have any way of knowing how many true anointed there really are on the earth. They close be saying that it isn't important that they know either.
Funny.....while the number was falling.....it was "proof" of how close the end was. Now that the number is sky-rocketing upward....the number no longer matters.
My guess is that soon they will stop printing the number alltogether. The higher it goes, the more of a black eye it is