Year	Number of
1990	596.37
1991	613.39
1992	577.94
1993	554.57
1994	533.97
1995	516.55
1996	509.42
1997	501.45
1998	494.13
1999	499.51
2000	507.14
2001	495.49
2002	502.41
2003	525.44
2004	547.48
2005	555.16
2006	554.22
2007	560.72
2008	569.92
2009	582
2010	594.11
2011	607.82
2012	625.48
2013	644.74
2014	664.62
2015	688.84
2016	712.41