Year	Number of
1990	65.09
1991	66.24
1992	67.7
1993	69.58
1994	72.07
1995	75.98
1996	78.25
1997	82.86
1998	86.69
1999	93.59
2000	100.13
2001	102.07
2002	102.32
2003	107.93
2004	109.63
2005	109.61
2006	110.55
2007	106.87
2008	104.67
2009	108.19
2010	104.33
2011	103.01
2012	103.94
2013	104.97
2014	106.59
2015	108.57
2016	110.3