See the section on “Data Quality" in Chapter 1 for a description of the quality criteria. First, however, to give an idea of how the position of both women and men has improved in absolute terms over the past 100 years, statistics on average women and men in the 1900s, 1950s and 2000s are provided in Figure 12.1. These estimates are population-weighted averages covering at least 40% of the world’s population, where missing countries are imputed to alleviate a bias against developing countries for which less statistical material is available. By the 1950s, however, she could expect to live 12 years longer and would marry just before her 20th birthday.