Year	Number of
1990	369.82
1991	369.57
1992	368.57
1993	367.95
1994	369.17
1995	373.14
1996	378.37
1997	387.09
1998	398.31
1999	410.57
2000	423.39
2001	433.09
2002	443.76
2003	454.92
2004	466.27
2005	477.98
2006	488.94
2007	499.33
2008	510.05
2009	521.48
2010	534.26
2011	546.34
2012	560.26
2013	575.51
2014	591.99
2015	609.63
2016	629.05