Year	Number of
1990	76.52
1991	79.65
1992	83.28
1993	86.67
1994	90.36
1995	92.85
1996	100.27
1997	107.22
1998	112.46
1999	123.64
2000	133.57
2001	137.81
2002	142.18
2003	144.56
2004	148.39
2005	152.51
2006	158.27
2007	163.08
2008	166.67
2009	172.34
2010	179.32
2011	185.6
2012	192.71
2013	197.91
2014	206.6
2015	212.4
2016	219.31