Year	Number of
1990	70.08
1991	72.58
1992	75.26
1993	78.14
1994	81.17
1995	84.36
1996	87.72
1997	91.26
1998	95.03
1999	99.09
2000	103.5
2001	106.96
2002	110.68
2003	114.72
2004	119.08
2005	123.79
2006	128.14
2007	132.81
2008	138
2009	143.58
2010	149.57
2011	154.37
2012	159.45
2013	164.74
2014	170.45
2015	176.64
2016	183.29