Year	Number of
1990	303.69
1991	299.12
1992	299.42
1993	300.97
1994	302.84
1995	307.31
1996	302.83
1997	300.31
1998	297.21
1999	301.66
2000	306.16
2001	308.85
2002	317.45
2003	324.11
2004	350.24
2005	355.62
2006	357.16
2007	363.78
2008	371.98
2009	381.77
2010	392.24
2011	401.11
2012	411.14
2013	421.34
2014	430.97
2015	444.78
2016	459.26