Year	Total
1985	10987000000
1986	12396000000
1987	13267000000
1988	12891000000
1989	14508000000
1990	14610000000
1991	14900000000
1992	13100000000
1993	12637000000
1994	10496000000
1995	9800000000
1996	10100000000
1997	9498000000
1998	9416000000
1999	8860000000
2000	9943000000
2001	10614000000
2002	10707000000
2003	10920000000
2004	11980000000
2005	12819000000
2006	13650000000
2007	14880000000
2008	15000000000
2009	16000000000
2010	16700000000
2011	17200000000
2012	17800000000
2013	18900000000
2014	20100000000
2015	21500000000
2016	22575000000