Year	Number of
1990	350.63
1991	362.8
1992	365.47
1993	372.25
1994	390.5
1995	399.89
1996	409.61
1997	397.73
1998	389.04
1999	386.75
2000	374.38
2001	370.52
2002	392.04
2003	405.39
2004	428.28
2005	438.41
2006	456.72
2007	470.65
2008	471.83
2009	463.63
2010	460.25
2011	462.44
2012	461.05
2013	458.6
2014	457.22
2015	471.92
2016	467.46