Year	Number of
1990	485.36
1991	490.11
1992	493.76
1993	495.65
1994	497.81
1995	500.83
1996	489.84
1997	479.47
1998	469.19
1999	460.63
2000	453.97
2001	450.33
2002	448.5
2003	449.85
2004	451.1
2005	451.81
2006	441.28
2007	430.44
2008	419.59
2009	411.16
2010	405.9
2011	404.55
2012	405.56
2013	406.86
2014	406.69
2015	404.56
2016	402.11