Year	Number of
1990	301.48
1991	308.63
1992	314.75
1993	322.32
1994	332.41
1995	338.4
1996	347.05
1997	364.53
1998	377.71
1999	383.85
2000	395.77
2001	405.31
2002	417.87
2003	432.1
2004	434.43
2005	449.27
2006	456.18
2007	477.72
2008	491.23
2009	502.05
2010	515.87
2011	530.6
2012	545.43
2013	562.27
2014	578.2
2015	592.07
2016	607.05