Year	World Bank estimate
1993	26.6
1996	25.8
2004	27.5
2005	26.9
2006	26.7
2007	26
2008	26.3
2009	26.2
2010	26.6
2011	26.4
2012	26.1
2013	26.5
2014	25.9
2015	25.9