Year	Total
1987	280000
1988	690000
1989	1490000
1990	2700000
1991	3960000
1992	5490000
1993	6300000
1994	7100000
1995	7652000
1996	8850000
1997	10100000
1998	12100000
1999	14600000
2000	16484000
2001	17078000
2002	17272000
2003	17581000
2004	20683000
2005	18952000
2006	17231000
2007	16262000
2008	15154000
2009	16666000
2010	15563000
2011	15769000
2012	17305000
2013	17390000
2014	18050000
2015	17437000
2016	15993000