Year	Number of
1990	274.51
1991	277.66
1992	285.74
1993	290.82
1994	303.45
1995	319.7
1996	332.97
1997	338.06
1998	346.9
1999	354.11
2000	365.85
2001	374.77
2002	383.52
2003	391.69
2004	403.7
2005	413.21
2006	424.75
2007	435.13
2008	450.29
2009	472.34
2010	490.6
2011	507.93
2012	523.36
2013	538.65
2014	551.47
2015	565.77
2016	581.15