Year	Total
1985	22506000000
1986	24168000000
1987	23629000000
1988	23039000000
1989	24070000000
1990	26132000000
1991	24747000000
1992	23627000000
1993	24442000000
1994	25712000000
1995	26774000000
1996	25760000000
1997	25347000000
1998	26032000000
1999	28407000000
2000	31158000000
2001	32046000000
2002	32427000000
2003	31147000000
2004	30543000000
2005	31294000000
2006	31227000000
2007	27907000000
2008	29309000000
2009	26074000000
2010	27720000000
2011	28135000000
2012	28393000000
2013	28590000000
2014	27254000000
2015	27191000000
2016	27452000000