I think that people who care about their country and the people living in it, will vote. In a country where politics are a major part of what's going on, and important decisions have to be taken every single day, the vast majority of the nation's populace want a good leader in charge, and would also want to pick that leader themselves.
Here we usually have 80-90 percent of the people voting, which makes sense considering how critical things are here. When the the burning question is whether to increase tax on coffee, it's obvious why most people won't vote... but when the outcome of the election can determine how people will live or die, they'd better vote.
