Year	Number of
1990	362.98
1991	370.84
1992	385.87
1993	388.21
1994	401.4
1995	408.67
1996	415.03
1997	423.43
1998	424.64
1999	432.02
2000	433.66
2001	446.18
2002	455.12
2003	465.43
2004	474.34
2005	477.86
2006	486.03
2007	488.69
2008	493.33
2009	499.85
2010	508.02
2011	521.66
2012	537.09
2013	553.21
2014	565.31
2015	569.4
2016	575