Year	Number of
1990	71.21
1991	73.61
1992	75.94
1993	78.33
1994	80.79
1995	83.8
1996	87.18
1997	90.76
1998	94.32
1999	98.7
2000	103.43
2001	106.46
2002	109.42
2003	116.41
2004	122.25
2005	126.88
2006	132.95
2007	139.02
2008	144.18
2009	150.71
2010	161
2011	173.44
2012	186.26
2013	201.05
2014	219.5
2015	234.98
2016	250.33