Year	Number of
1990	90.93
1991	95.07
1992	94.02
1993	93.7
1994	94.59
1995	94.94
1996	95.52
1997	96.67
1998	93.57
1999	94.19
2000	92.04
2001	88.65
2002	86.72
2003	86.51
2004	85.44
2005	82.08
2006	79.12
2007	77.57
2008	75.47
2009	74.83
2010	74.14
2011	74.26
2012	75.57
2013	75.35
2014	72.95
2015	75.07
2016	73.97