Year	Number of
1990	341.25
1991	363.46
1992	393.88
1993	421.5
1994	455.44
1995	480.21
1996	496.71
1997	507.98
1998	515.55
1999	506.34
2000	496.82
2001	496.48
2002	486.86
2003	495.85
2004	498.43
2005	499.95
2006	504.43
2007	505.49
2008	509.55
2009	512.55
2010	515.2
2011	521.99
2012	524.36
2013	528.15
2014	546
2015	565.51
2016	585.86