Year	Number of
1990	503.08
1991	486.4
1992	471.67
1993	464.02
1994	458.93
1995	457.08
1996	455.66
1997	447.97
1998	439.25
1999	430.62
2000	426.29
2001	411.34
2002	399.13
2003	388.44
2004	380.29
2005	372.78
2006	362.01
2007	357.77
2008	354.33
2009	346.16
2010	342.8
2011	344.64
2012	340.82
2013	341.97
2014	336.22
2015	336.62
2016	337.94