Year	Number of
1990	196.13
1991	206.81
1992	217.61
1993	239.61
1994	252.21
1995	262.35
1996	269.66
1997	278.94
1998	294.28
1999	313.84
2000	334.8
2001	366.62
2002	393.21
2003	422.35
2004	449.32
2005	483.22
2006	515.81
2007	545.34
2008	538.54
2009	521.68
2010	537.1
2011	538.06
2012	539.36
2013	539.48
2014	529.74
2015	529.38
2016	533.58