Year	Number of
1990	219.92
1991	229.19
1992	239.11
1993	246.37
1994	261.01
1995	268.44
1996	277.79
1997	286.57
1998	295.79
1999	301.16
2000	302.16
2001	306.86
2002	310.28
2003	314.55
2004	324.8
2005	334.1
2006	342.01
2007	349.12
2008	358.21
2009	366.28
2010	374.88
2011	383.6
2012	393.09
2013	404.29
2014	415.38
2015	428.45
2016	440.74