Year	Number of
1990	368.27
1991	385.05
1992	402.98
1993	422.45
1994	445.1
1995	472.09
1996	457.17
1997	444.79
1998	434.02
1999	423.63
2000	413.47
2001	421.27
2002	428.91
2003	437.63
2004	447.1
2005	458.01
2006	453.73
2007	450.58
2008	447.84
2009	446.02
2010	445
2011	452.76
2012	460.61
2013	468.42
2014	476.03
2015	483.89
2016	491.44