Some of the biggest elections include India, the world’s largest democracy with 800 million eligible voters, Indonesia, with 187 million registered voters, and Nigeria who has 84 million registered voters.

How old must you be to vote? Ninety percent of the world votes at the age of 18. If you’re 16, you’d be eligible to vote in Argentina, Austria, Brazil, Cuba, Ecuador, Malta, and Nicaragua. You'll need to be at least 21 to vote in Lebanon, Malaysia, Samoa, Singapore and Tonga.

When could all citizens vote? In 1893, New Zealand became the first country in the world to grant women the right to vote. By the 1950s, two-thirds of countries around the world had adopted universal suffrage, which allows all adult citizens equal rights to vote. The last European country to allow women to vote was Switzerland in 1971. In 1994, South Africa became the last African democracy to give equal voting rights to all following the end of apartheid. In Afghanistan, women gained and lost the right to vote several times. They have continuously held the right to vote since 2004.

Most countries hold elections every 4-5 years. The country with the most frequently held elections is San Marino, where a leader from one of two alternating parties is elected every six months.

How many terms can each leader serve? Most leaders can either serve one or two terms in office. It’s not uncommon, however, for a country’s leader to have an unspecified term limit. In some countries, such as the United Kingdom and New Zealand, heads of government serve until they resign or lose majority support of parliament. Other countries without term limits, like Venezuela, let voters petition for a recall election after a certain period of time.

In which countries can prisoners vote? Countries have different laws pertaining to whether or not prisoners can vote. Roughly a third of countries around the world allow prisoners to vote. Another one-third allow some prisoners to vote, usually based on the type of prison sentence or on local laws. The remaining one-third of countries do not allow prisoners to vote altogether.

Al Jazeera