If I recall correctly, the year 1984 has way more occurrences than other years because they were 'celebrating' the 70th anniversary of 1914 with a four-part series on 1914.
Checking my most recent Watchtower coaster, 1914 was mentioned 108 times in just four WT issues during 1984 -- April 1, April 15, May 1, and May 15. This series sported titles such as "1914 a Marked Year", "1914 A Focal Point", "1914--It Changed Your Life", "What 1914 Could Mean for You", and "1914--The Generation that WILL NOT Pass Away." (what a joke, esp that last one)
Looking at their CD, it seems to me that mentions of 1914 dropped off in the WT mag around 1995 - which (surprise!) is the year they changed the meaning of a 'generation'. Oh they still talk about 1914, they just don't talk about the 1914 generation any more.
The WT is actually pushing 1914 more than ever. The newest video they put out, intended for teens and young adults, tells 'em to study 1914 and firmly believe it so they can teach it to their Bible studies. Of course that info never shows up in the statistics.
Unfortunately for them, they have so much of their belief system tied up in 1914 that they would require a complete doctrinal overhaul to drop it.
LOL at the idea that they actually believe teens have Bible studies.