Year	Number of
1990	117.33
1991	120.7
1992	124.35
1993	128.37
1994	132.32
1995	136.35
1996	137.37
1997	138.51
1998	139.76
1999	140.79
2000	141.62
2001	143.14
2002	144.52
2003	145.58
2004	146.86
2005	148.28
2006	152.56
2007	157.46
2008	162.47
2009	167.53
2010	173.05
2011	175.44
2012	178.41
2013	181.28
2014	184.29
2015	188.84
2016	193.97