Year	Number of
1990	183.86
1991	192.89
1992	202.45
1993	212.79
1994	223.95
1995	235.62
1996	248.66
1997	261.95
1998	275.94
1999	290.93
2000	309.22
2001	329.27
2002	348.99
2003	369.24
2004	390.81
2005	414.48
2006	434.22
2007	457.56
2008	483.29
2009	511.1
2010	539.19
2011	562.98
2012	575.54
2013	587.9
2014	600.69
2015	613.96
2016	630.99