Year	Number of
1990	154.15
1991	151.87
1992	149.67
1993	148.9
1994	149.62
1995	149.87
1996	148.84
1997	151.61
1998	140.68
1999	136.4
2000	128.77
2001	125.97
2002	118.19
2003	116.91
2004	112.05
2005	110.56
2006	109.39
2007	108.91
2008	110.1
2009	113.99
2010	114.41
2011	111.92
2012	110.26
2013	109.9
2014	107.15
2015	107.42
2016	107.31