Year	Number of
1990	70.42
1991	72.06
1992	73.8
1993	75.94
1994	78.4
1995	80.8
1996	83.15
1997	85.27
1998	86.75
1999	88.03
2000	88.41
2001	88.24
2002	88.17
2003	88.2
2004	89.32
2005	90.18
2006	90.51
2007	88.8
2008	87.92
2009	88.55
2010	89.95
2011	91.65
2012	93.11
2013	93.73
2014	93.94
2015	94.02
2016	94.24