Measures of gender equality or inequality are statistical tools employed to quantify the concept of gender equality. There are over three hundred different indicators used to measure gender equality, as well as a number of prominent indices. The most prominent indices of gender equality include UNDP's Gender-related Development Index (GDI) and the Gender Empowerment Measure (GEM), introduced in 1995. More recent measures include the Gender Equity Index (GEI) introduced by Social Watch in 2004, the Global Gender Gap Index (GGGI) developed by the World Economic Forum in 2006, and the Social Institutions and Gender Index of OECD Development Centre from 2007. Indicators Sample indicators of gender equality include gender-sensitive breakdowns of the number or percentages of positions as legislators or senior managers, presence of civil liberties such as freedom of dress or freedom of movement, social indicators such as ownership rights such as access to banks or land, crime indicators such as violence against women, health and education indicators such as life expectancy, educational attainment, and economic indicators such as gender pay gap, labor force participation or earned income. To reduce the number of individual statistics to be cited, several indices composed of aggregated indicators are commonly used. Indices Gender-related Development Index GDI is a gender-focused development of the Human Development Index, measures the development levels in a country corrected by the existing gender inequalities. It addresses gender-gaps in life expectancy, education, and incomes. It uses an “inequality aversion” penalty, which creates a development score penalty for gender gaps in any of the categories of the Human Development Index which include life expectancy, adult literacy, school enrollment, and logarithmic transformations of per-capita income. In terms of life expectancy, the GDI assumes that women will live an average of five years longer than men. Additionally, in terms of income, the GDI considers income-gaps in terms of actual earned income. The GDI cannot be used independently from the Human Development Index (HDI) score and so, it cannot be used on its own as an indicator of gender-gaps. Only the gap between the HDI and the GDI can actually be accurately considered; the GDI on its own is not an independent measure of gender-gaps. Gender Empowerment Measure GEM was developed at the same time as GDI, but is seen as more specialized. It included dimensions not present in GDI (and correspondingly, HDI), such as rights and access to power. The GEM was designed