Year	Number of
1990	79.11
1991	82.55
1992	86.18
1993	89.7
1994	93.04
1995	96.38
1996	92.15
1997	88.01
1998	84.31
1999	81.23
2000	78.73
2001	76.94
2002	75.74
2003	75.11
2004	74.79
2005	74.68
2006	75.73
2007	76.78
2008	78.39
2009	80.13
2010	82.24
2011	83.96
2012	85.91
2013	88.48
2014	91.35
2015	94.57
2016	97.92