Year	Number of
1990	128.83
1991	132.61
1992	135.03
1993	136.17
1994	136.87
1995	137.06
1996	137.72
1997	138.7
1998	141.25
1999	144.14
2000	146.98
2001	150.05
2002	153.97
2003	161.15
2004	169.55
2005	178.92
2006	189.04
2007	192.98
2008	202.28
2009	201.83
2010	202.12
2011	204.28
2012	205.56
2013	206.97
2014	208.57
2015	218.1
2016	218.2