Year	Number of
1990	141.47
1991	139.75
1992	146.53
1993	142.59
1994	136.84
1995	134.73
1996	135.13
1997	137.26
1998	143.39
1999	143.91
2000	149.22
2001	155.06
2002	154.63
2003	160.4
2004	167.82
2005	179.36
2006	190.87
2007	192.89
2008	204.34
2009	206.72
2010	206.24
2011	205.39
2012	202.26
2013	198.28
2014	197.96
2015	206.22
2016	208.37