Year	Number of
1990	333.53
1991	344.78
1992	357.9
1993	373.24
1994	388.03
1995	404.06
1996	410.02
1997	415.47
1998	417.8
1999	422.65
2000	427.44
2001	432.12
2002	437.57
2003	441.95
2004	447.19
2005	452.02
2006	456.04
2007	461
2008	467.08
2009	474.58
2010	482.74
2011	494.03
2012	505.16
2013	518.07
2014	532.99
2015	554.8
2016	575.02