Year	Number of
1990	69.03
1991	69.57
1992	70.2
1993	70.11
1994	70.31
1995	68.53
1996	67.53
1997	69.53
1998	68.81
1999	67.63
2000	65.45
2001	65.42
2002	65.83
2003	67.23
2004	64.61
2005	64.47
2006	64.28
2007	63.81
2008	63.6
2009	65.25
2010	65.89
2011	67.84
2012	68.72
2013	67.99
2014	68.6
2015	71.07
2016	72.91