Year	Number of
1990	448.06
1991	462.2
1992	478.73
1993	496.37
1994	513.86
1995	530.39
1996	540.52
1997	545.07
1998	547.73
1999	552.53
2000	555.88
2001	558.33
2002	562.56
2003	566.46
2004	572.21
2005	578.64
2006	580.77
2007	582.37
2008	585.69
2009	589.33
2010	592.96
2011	593.36
2012	599.34
2013	605.37
2014	612.73
2015	620.8
2016	631.35