- Life satisfaction inequality: This data is indicative of how much citizens differ in enjoyment of their life-as-a-whole.Life-satisfaction assessed by means of surveys in samples of the general population. Scores may be too low in some countries, due to under sampling of rural and illiterate population. In this ranking the focus is not on the level of happiness in the country, but on inequality in happiness among citizens.Inequality in happiness can be measured by the dispersion of responses to survey-questions. The degree of dispersion can be expressed statistically in the standard deviation and surveys items rated on a 10 step numerical scale are particularly usefull for that purpose. Most scores are based on responses to the following question: "All things considered, how satisfied or dissatisfied are you with your life-as-a-whole now? 1 dissatisfied to10 satisfied".
- Roller coasters: Number of roller coasters in each country. Includes both wooden and steel constructions.
- Roller coasters per million: Number of roller coasters in each country. Includes both wooden and steel constructions. Figures expressed per million population for the same year.
SOURCES: World Database of Happiness, Happiness in Nations, Rank Report 2004/3b. Equality of happiness in 90 nations 1990-2000. How much citizens differ in enjoyment of their life as a whole; The Roller Coaster Database, 2006.; The Roller Coaster Database, 2006. 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.