Year	Number of
1990	57.11
1991	59.69
1992	62.44
1993	65.59
1994	68.76
1995	72.22
1996	75
1997	77.78
1998	80.85
1999	84.01
2000	87.22
2001	88.14
2002	88.87
2003	89.65
2004	90.31
2005	91.26
2006	92.5
2007	93.71
2008	95.32
2009	97.09
2010	99.17
2011	101.23
2012	103.87
2013	106.35
2014	109.12
2015	112.16
2016	115.37