Year	Number of
1990	91.56
1991	92.28
1992	92.11
1993	90.59
1994	88.35
1995	87.07
1996	87.28
1997	89.12
1998	89.84
1999	91.63
2000	93.83
2001	99.57
2002	106.79
2003	114.12
2004	120.81
2005	128.05
2006	136.7
2007	144.25
2008	151.51
2009	158.53
2010	165.66
2011	174.66
2012	182.87
2013	190.3
2014	197.59
2015	204.68
2016	215.78