Year	World Bank estimate
1990	42
1997	58.2
1999	58.1
2000	61.6
2001	57.4
2002	59.3
2004	55
2005	58.5
2006	56.7
2007	54.5
2008	50.8
2009	49.2
2011	46.1
2012	46.6
2013	47.6
2014	47.8
2015	46.7
2016	44.6
2017	44