The World Bank has been revising its definition and benchmarks to measure poverty since 1990-1991, with a $0.2 per day income on purchasing power parity basis as the definition in use from 2005 to 2013. Some semi-economic and non-economic indices have also been proposed to measure poverty in India. For example, in order to determine whether a person is poor, the Multi-dimensional Poverty Index places a 13% weight on the number of years that person spent in school or engaged in education and a 6.25% weight on the financial condition of that person.