Year	Number of
1990	126.28
1991	131.69
1992	137.86
1993	144.62
1994	151.59
1995	158.63
1996	167.72
1997	176.91
1998	186.41
1999	196.4
2000	207.26
2001	220.17
2002	234.44
2003	250.28
2004	266.92
2005	284.24
2006	296.29
2007	308.16
2008	320.66
2009	334.31
2010	349.71
2011	361.64
2012	375.24
2013	389.88
2014	405.54
2015	422.01
2016	437.79