Year	World Bank estimate
1998	46.4
2000	31
2001	30.2
2002	30.3
2003	28.7
2004	34.8
2005	32.6
2006	37.4
2007	33.9
2008	31.5
2009	29.9
2010	30.1
2011	27.8
2012	27.4
2013	28.8
2014	26.8
2015	29
2016	26.8
2017	27.3