Year	Number of
1990	153.15
1991	150.83
1992	148.7
1993	148.22
1994	149.65
1995	150.43
1996	149.78
1997	152.41
1998	141.66
1999	137.47
2000	130.38
2001	127.8
2002	119.91
2003	118.62
2004	113.94
2005	112.61
2006	111.72
2007	111.64
2008	113.23
2009	117.56
2010	118.57
2011	116.53
2012	115.43
2013	115.71
2014	113.78
2015	115
2016	115.71