ILoveTTATT: What the graph tells us is that there is a clear trend towards hunting down inactive and/or irregular publishers.
Keeping the faithful flock active and still part of the "official" count has always been an ongoing problem for the org. The push to keep people active has been documented in their yearbooks.
For example, the 1967 yearbook (page 35) says this about inactive ones:
It is evident from the year's report that a number
of persons who used to be Jehovah's witnesses
found reasons sufficient to convince themselves
that they need no longer worship and serve Jehovah
and attend meetings at the house of their
God. Such ones drifted away. However, there
is still an opportunity before one dies to ask for
forgiveness and share in God's goodness by returning
to the ministry.
If all those who dedicated their lives to the
Most High God Jehovah in former years had
stayed in his organization right up to and during
the year 1966, there would have been a greater
increase in the number of regular publishers than
we have had. While the final report shows there
were 1,058,675 regular Kingdom publishers engaging
in the field ministry each month of the past
service year, still this is an increase of only 24,407
over last year. But 58,904 were baptized. 'Where
were the other 34,497 that cannot be accounted
for? Allowing for one percent of the population
dying in a year's time would mean a drop of
about 10,000 persons. But where are the others?
Has materialism attracted them? Has the loose
living and immoral conduct of the world ensnared
some of them? Where is that love for Jehovah's
organization and his service that they once had?
As we analyze the report for the world, as
set forth in the chart on pages 36-43, you will
see that some countries had no increase at all.
Are we to believe that the harvest is over in such
countries? No! Because there were some persons
being baptized...
The presentation and interpretation of the stats in that '67 yearbook are rather skewed, but, the intent remains - the JWs were experiencing a slow down at that time (according to the "official" count) and they were due for a dressing down for their negligence to the org.
The slowing down of increase and/or registering a decrease has, in the past, been the force that determined doctrine. In 1967, the org was geared up for an Armageddon scare to get those inactive ones out in service. In later years, the hourly requirement and form of service has been adapted to make it easier to 'get counted' to keep those precious numbers up.
I wonder what strategy the org will use this time to keep those numbers up. Good thing for internet witnessing or the publisher number would be even harder to keep on an even keel