Year	Number of
1990	349.69
1991	348.87
1992	349.92
1993	350.86
1994	356.94
1995	359.86
1996	359.2
1997	371.14
1998	380.32
1999	395.31
2000	417.64
2001	426.12
2002	439.51
2003	450.54
2004	465.42
2005	484.51
2006	491.13
2007	501.87
2008	508.99
2009	517.08
2010	532.93
2011	545.86
2012	557.49
2013	570.31
2014	580.1
2015	590.37
2016	603.08