Perhaps Monte Sahlin could help with this, William, but my memory is that in North America, one out of ten congregations hold the majority of members, and those largest churches are almost all around institutions. That means that there are relatively few Adventists spread out in places like rural Nebraska and small-city Ohio, but lots of them at Lincoln, Kettering, Loma Linda, and so on—the Adventist ghettos concentrated around Adventist institutions.