Year	Total
1985	20702000000
1986	21542000000
1987	22909000000
1988	23572000000
1989	23300000000
1990	23200000000
1991	23356000000
1992	19673000000
1993	19100000000
1994	17571000000
1995	17044000000
1996	17088000000
1997	16800000000
1998	17900000000
1999	18100000000
2000	18700000000
2001	18969000000
2002	18701000000
2003	21286000000
2004	21744000000
2005	22872000000
2006	24543000000
2007	21847000000
2008	21642000000
2009	18869000000
2010	18709000000
2011	20294000000
2012	22988000000
2013	23354000000
2014	24728000000
2015	24688000000
2016	24974000000