Year	Number of
1990	157.66
1991	164.55
1992	170.65
1993	177.16
1994	184
1995	191.46
1996	196.79
1997	202.09
1998	208.72
1999	214.5
2000	219.05
2001	225.09
2002	231.46
2003	237.39
2004	242.96
2005	247.7
2006	252.25
2007	257.24
2008	261.82
2009	268.26
2010	275.03
2011	283.72
2012	295.47
2013	305.57
2014	317.71
2015	332.99
2016	350.09