Year	Number of
1990	59.42
1991	63.58
1992	66.11
1993	69.17
1994	71.33
1995	74.84
1996	75.17
1997	74.19
1998	79.32
1999	84.11
2000	84.8
2001	89.48
2002	92.83
2003	97.1
2004	98.52
2005	102.11
2006	103.28
2007	108.32
2008	106.35
2009	106.31
2010	109.59
2011	109.3
2012	110.27
2013	111
2014	112.17
2015	113.68
2016	114.62