Year	Number of
1990	78.72
1991	80.39
1992	82.26
1993	83.6
1994	86.11
1995	87.39
1996	89.03
1997	93.29
1998	99.95
1999	107.86
2000	115.3
2001	120.71
2002	126.66
2003	134.64
2004	141.25
2005	145.71
2006	146.18
2007	147.9
2008	152.73
2009	158.41
2010	164.97
2011	169.75
2012	174.72
2013	180.66
2014	186.22
2015	192.02
2016	197.9