Year	Number of
1990	204.9
1991	205.98
1992	207.19
1993	208.61
1994	210.08
1995	212.17
1996	213.82
1997	216.16
1998	218.59
1999	221.63
2000	225.37
2001	229.73
2002	234.54
2003	239.86
2004	245.53
2005	252.08
2006	257.52
2007	263.01
2008	269.53
2009	276.48
2010	283.95
2011	292.61
2012	302.2
2013	312.64
2014	323.58
2015	334.93
2016	346.43