Year	Number of
1990	87.08
1991	85.53
1992	84.5
1993	81.29
1994	78.84
1995	75.16
1996	72.81
1997	70.94
1998	69.56
1999	69.48
2000	69.56
2001	70.53
2002	71.64
2003	73.08
2004	74.4
2005	75.41
2006	76.68
2007	79.07
2008	82.27
2009	81.97
2010	81.79
2011	81.65
2012	82.11
2013	82.61
2014	84.27
2015	86.36
2016	89.49