Are there any statistics on percent of “off the derech”, and how do you define “off the derech”?
If I wear a fedora or a homburg, and my son wears a knit yarmulke, is he off the derech? If someone isn’t going to work on Shabbos, eating pork, and marrying a non-Jew, are they really off the derech? A frum juvenile delinquent is still frum. In the past, most orthodox synagogues in America had trouble finding a minyan of Shomer Shabbos, and parents routinely were asking how to act when eating in their children’s home (as in “is it okay to drink water in a glass cup?”) – and you don’t see that any more.