Year	Number of
1990	290.26
1991	300.34
1992	313.61
1993	324.94
1994	333.39
1995	352.41
1996	362.14
1997	370.29
1998	381.38
1999	389.88
2000	405.2
2001	422.35
2002	441.85
2003	452.97
2004	469.72
2005	486.51
2006	496.54
2007	508.26
2008	516.79
2009	529.27
2010	541.73
2011	546.59
2012	548.38
2013	547.73
2014	556.55
2015	571.14
2016	586.64