I have seen very few past about 1993. The last big push was in the mid 1980s, and that was before anyone had sources of information to cross-reference the witlesses with. People with little Bible knowledge and a poor social network were scammed into joining the cancer during that period, which seems to have ended roughly in 1993.
However, now that information is a mouse click away for most people, it will only be those that are mentally retarded, poorly educated, lacking resources to buy computers and get online, those going through a major crisis, those on drugs or drunk when they accept a study, children of witlesses, and those who the hounders manage to coerce into joining that are going in. People that are well off and well educated should be able to cross-reference the religion and find all the holes in it, and probably will not be signing on.