Year	Number of
1990	218.36
1991	215.04
1992	216.27
1993	216.56
1994	219.55
1995	214.97
1996	209.47
1997	207.27
1998	203.81
1999	208.86
2000	211.98
2001	216.01
2002	219.49
2003	224.5
2004	229.77
2005	235.69
2006	241.14
2007	246.2
2008	251.76
2009	257.5
2010	263.39
2011	269.33
2012	275.56
2013	282.06
2014	289.11
2015	296.68
2016	305.63