Year	Number of
1990	358.73
1991	358.25
1992	358.18
1993	357.74
1994	360.69
1995	365.68
1996	371.97
1997	380.77
1998	391.23
1999	397.02
2000	402.27
2001	407
2002	416.62
2003	427.21
2004	436.82
2005	446.73
2006	456.46
2007	466.63
2008	476.9
2009	486.11
2010	498.27
2011	508.01
2012	525.11
2013	537.12
2014	552.73
2015	569.47
2016	585.51