Year	Number of
1990	99.48
1991	104.7
1992	100.12
1993	109.63
1994	111.13
1995	105.27
1996	97.1
1997	93.17
1998	92.74
1999	85.1
2000	86.91
2001	87.74
2002	83.13
2003	82.11
2004	78.87
2005	80.44
2006	80.57
2007	79.71
2008	78.39
2009	74.5
2010	69.03
2011	70.65
2012	69.06
2013	69.21
2014	67.66
2015	66.22
2016	65.49