Year	Number of
1990	256.87
1991	264.51
1992	273.86
1993	280.41
1994	292.89
1995	298.9
1996	306.88
1997	318.13
1998	338.35
1999	356.56
2000	367.31
2001	370.5
2002	375.93
2003	389.86
2004	399.11
2005	398.74
2006	392.34
2007	390.56
2008	400.51
2009	412.64
2010	427.86
2011	437.2
2012	449.79
2013	468.87
2014	488.08
2015	508.13
2016	527.45