Year	Number of
1990	514.57
1991	503.86
1992	479.92
1993	457.95
1994	445.48
1995	429.66
1996	425.16
1997	423.17
1998	425.52
1999	433.77
2000	445.73
2001	460.1
2002	475.29
2003	493.11
2004	512.33
2005	532.03
2006	548.56
2007	564
2008	580.72
2009	597.29
2010	611.83
2011	629.48
2012	645.26
2013	662.22
2014	679.24
2015	696.21
2016	715.5