The prophecy of Daniel was that the stone cut out of the mountains without hands would roll forth, grind to dust the prior world orders, become a great mountain, and fill the whole earth. (Daniel 2: 34-35.) Daniel's interpretation included that God will establish a kingdom in the latter days which shall never be destroyed, nor left to other people. It will break into pieces and consume all other kingdoms and stand forever. (Id. verses 44-45.)
To the extent the Church claims to be this kingdom, or rock rolling forth, it should be expected to increase in size, and momentum, as it rolls forth to fill the earth.
The Church ceased to distinguish between baptisms for "children of record" and "converts" some years ago. Numbers are given in April General Conference. Last April's conference statistical report included this statement: "Converts Baptized: 265,593." There was a separate category for "Children of Record." but there was no separate category for "Baptisms of Children of Record." That used to be a separate category. Since it's elimination, I have had the impression that "Converts Baptized" included all numbers, including baptisms of "Children of Record." If that is so, then for the last recorded numbers of baptisms you would need to go back to eight years earlier, take the number of Children of Record, and subtract that number from the "Converts Baptized number to get the actual number of Converts. Eight years earlier from the number given in last General Conference, the statistical report announced that there was an increase of 81,450 Children of Record. So the actual number of baptisms of Converts alone would be 184,143. That appears to me to be the real number of Converts, exclusive of baptisms of Children of Record.
Now the Church hasn't provided this separate number for Children of Record for about a decade now. And I can't be certain that the "Converts Baptized" category is actually an amalgamation of the two. But I think it is. If so, the decline from the time of President Kimball to today is more than significant, it is catastrophic.
I believe the only reason to convert to our faith is our doctrine. Since the Church has de-emphasized doctrine, the trend of lowering missionary success has confirmed my belief in the necessity of teaching doctrine. Not just in the Teach My Gospel program, but in every aspect of the Church, from Sunday School and Primary to Stake and General Conferences. Doctrine is what distinguishes us.
Deseret Book has actually told me that "doctrine books do not sell." They are interested in fiction, which can be read in one or two settings.