- Invalid votes: The number of invalid votes, as reported by each country.
- Registered voter turnout: The proportion of registered voters who actually voted.
- Total vote: The total number of votes cast in the relevant election. Total vote includes valid and invalid votes, as well as blank votes in cases where these are separated from invalid votes. More information on valid, invalid and blank votes can be found at aceproject.org
- Turnout: The number of votes divided by the Voting Age Population figure, expressed as a percentage.
- Voter registration: The number of registered voters. The figure represents the number of names on the voters' register at the time that the registration process closes, as reported by the electoral management body.
- Voting age population: International IDEA has chosen to use not only the reported registration rate to calculate turnout percentages, but also the voting age population (VAP) which includes all citizens above the legal voting age
- Voting age population per 1000: International IDEA has chosen to use not only the reported registration rate to calculate turnout percentages, but also the voting age population (VAP) which includes all citizens above the legal voting age. Figures expressed per thousand population for the same year.
SOURCES: Institute for Democracy and Electoral Assistance 2003; Institute for Democracy and Electoral Assistance 2003. Population figures from World Bank: (1) United Nations Population Division. World Population Prospects, (2) United Nations Statistical Division. Population and Vital Statistics Report (various years), (3) Census reports and other statistical publications from national statistical offices, (4) Eurostat: Demographic Statistics, (5) Secretariat of the Pacific Community: Statistics and Demography Programme, and (6) U.S. Census Bureau: International Database.