Year	Number of
1990	155.45
1991	162.24
1992	170.1
1993	180.01
1994	190.99
1995	204.4
1996	210.54
1997	219.26
1998	229.13
1999	237.43
2000	247.7
2001	258.8
2002	269.16
2003	280.24
2004	291.13
2005	300.22
2006	308.49
2007	320.27
2008	334.62
2009	351.26
2010	367.83
2011	383.39
2012	398.76
2013	415.2
2014	434.18
2015	455
2016	476.66