Year	Number of
1990	58.79
1991	59.83
1992	61.12
1993	62.41
1994	63.84
1995	65.76
1996	66.77
1997	68.05
1998	69.85
1999	71.39
2000	72.72
2001	72.34
2002	74.02
2003	75.08
2004	77.72
2005	77.91
2006	80.73
2007	83.7
2008	85.85
2009	89.23
2010	91.32
2011	92.4
2012	95.77
2013	99.05
2014	102.12
2015	105.47
2016	108.32