Year	Number of
1990	70.27
1991	73.45
1992	76.48
1993	79.66
1994	82.88
1995	85.32
1996	90.66
1997	96.42
1998	100.93
1999	105.43
2000	112.38
2001	118.54
2002	124.33
2003	129.97
2004	135.65
2005	141.56
2006	146.55
2007	152.19
2008	156.34
2009	163.51
2010	171
2011	176.38
2012	183.16
2013	188.9
2014	194.67
2015	199.38
2016	204.47