(source, voting age is a minimum age established by law that a person must attain to be eligible to vote in a public election)
More on democracy as a human right. It goes without saying that the legal voting age isn’t a good indicator of the quality of democracy in a country. So you can’t use this information to judge whether a country respects the right to democracy. A very high legal voting age – which apparently doesn’t exist anywhere – would exclude large numbers of people from democratic participation. (There are other ways in which countries exclude large numbers of people; see here). On the other hand, there can be countries with a very low voting age but a seriously dysfunctional democracy. More human rights maps.