Year	Number of
1990	61.76
1991	60.77
1992	62.56
1993	63.18
1994	64.08
1995	65.51
1996	66.06
1997	66.22
1998	66.31
1999	64.91
2000	65.29
2001	64.86
2002	64.96
2003	65.89
2004	65.3
2005	63.92
2006	63.28
2007	63.7
2008	64.66
2009	64.99
2010	66.66
2011	66.59
2012	66.29
2013	68.24
2014	72.09
2015	73.75
2016	75.3