Year	Number of
1990	68.74
1991	67
1992	65.38
1993	67.9
1994	73.93
1995	77.86
1996	82.51
1997	83.52
1998	82.41
1999	82.6
2000	80.43
2001	76.37
2002	73.4
2003	74.75
2004	76.2
2005	78.11
2006	78.54
2007	79.93
2008	81.33
2009	80.72
2010	81.43
2011	80.94
2012	80.7
2013	81.46
2014	82.28
2015	83.63
2016	84.95