Year	Number of
1990	238.34
1991	209.94
1992	205.1
1993	209.05
1994	223.48
1995	263.35
1996	261.93
1997	276.14
1998	295.91
1999	309.85
2000	340.42
2001	358.94
2002	394.29
2003	407.32
2004	424.29
2005	443.23
2006	453.62
2007	461.81
2008	472.26
2009	473.07
2010	474.01
2011	469.19
2012	462.94
2013	460.34
2014	458.33
2015	461.94
2016	468.26