Year	Number of
1990	71.31
1991	73.8
1992	76.37
1993	79.18
1994	82.19
1995	84.57
1996	89.41
1997	94.81
1998	99.12
1999	103.37
2000	109.93
2001	115.88
2002	121.41
2003	126.7
2004	131.77
2005	137.36
2006	141.89
2007	146.97
2008	150.71
2009	156.88
2010	163.56
2011	168.46
2012	174.41
2013	179.74
2014	185.38
2015	190.1
2016	195.07