Year	Number of
1990	407.13
1991	418.09
1992	431.14
1993	449.63
1994	474.96
1995	502.69
1996	517.85
1997	522.47
1998	534.78
1999	536.24
2000	542.32
2001	536.62
2002	535.14
2003	534.31
2004	530.29
2005	516.73
2006	500.86
2007	489.68
2008	473.23
2009	465.62
2010	460.04
2011	450.86
2012	441.37
2013	428.92
2014	422.3
2015	414.19
2016	407.25