Year	Number of
1990	65.45
1991	64.68
1992	66.15
1993	68.53
1994	70.61
1995	73.57
1996	74.17
1997	75.69
1998	75.24
1999	74.81
2000	72.03
2001	69.5
2002	67.32
2003	69.08
2004	69.24
2005	69.41
2006	70.57
2007	72.77
2008	75
2009	76.86
2010	77.77
2011	80.01
2012	84.07
2013	87.68
2014	91.74
2015	96.07
2016	101.1