I GOT YER "NEW LIGHT" RIGHT HERE!
Or I only think I have an explanation for the statistical increase of 3%... This is speculative, but hear me out. At the time I wondered about this...
I don't have the records on hand, but starting about a year ago, a new box appeared on the report that congregation secretaries submit to hindquarters, er, I mean headquarters. In addition to the table layout for total hours, literature, return visits, bible studies, and report count of slips for the month for publishers, pioneers, and aux. pios., a separate new box appeared titled "Congregation Members - Active Publishers". Consequently, in addition to the number of active publishers for that one month, there was now a number turned in each month for the number of active publishers for the last 6 months, that would be a higher number. For example, in bOrgville congregation, for the month of December, the secretary received 52 publisher reports, 1 aux pio, and 4 reg pio reports. The total number of reports would be 57. However, the new box asking for the number of active publishers would receive the higher number of 62, since the 3 of the Fader family haven't reported in the last five months (consequently are 'irregular' and not yet 'inactive' until next "month six". At which time, the elders will try frantically to get them out at least one month before the CO returns and chews them out {both the elders and inactive... but mostly the elders, usually}), and in December a couple oldtimers had strokes, couldn't speak, and had no field service time (the Satan worshipping heathens). So, if WTBTS now uses 62 for the publisher count instead of the traditional 57 active publisher for the month, ta-da, instant increase... although no increase exists. The thing I would find surprising would be that using that statistic, I would think the publisher count would be up more like 8%.
I don't know, I hate to speculate, or go beyond what the Faithful and Discreet Slave has written. Oh, um, nevermind. I'm officially speculating without approval here. At the time that box appeared, I wondered why it was there. The next problem would be that next year the artificial peak wouldn't be new and would level off again to more like the 1.3% again.
Sorry I don't have time to research, but I wonder if a number game like this would be revealed in the total hours. The last CO visits have really pushed more hours, more hours, more hours.