I wonder if the d2d work is more likely being phased out, by means of initiatives like "trolly folly", jwTV and jw.org due to basic math lessons the GB have taken at JWfacts.com.
Total hours of FS worldwide for a given year namely 2013 [ 1,841,180,235 ],
divided by (an estimated) half the baptisms, namely those not recruited by their parents [ 0.5 X 277,344 ],
divided by a 10-hour-per-month publisher's hours per year [ 10 hours per month X 12 months ],
equals x-years of doorknocking by a 10-hour-per-month publisher per baptism via doorknocking.
Years = 1,841,180,235 / (0.5 X 277,344) / (10 X 12) = 110 years
In essence, using 2013 figures, it will take a 10-hour-per-month publisher (an average of) 110 years to generate 1 baptism via doorknocking.