Year	Number of
1990	94.11
1991	90.6
1992	91.12
1993	93.62
1994	95
1995	98.47
1996	97.98
1997	98.62
1998	97
1999	93.47
2000	86.46
2001	80.52
2002	74.89
2003	74.81
2004	72.67
2005	70.47
2006	69.68
2007	70.51
2008	71.23
2009	71.3
2010	69.94
2011	70.23
2012	72.01
2013	73.49
2014	75.36
2015	77.43
2016	80.24