Year	Number of
1990	131.33
1991	133.32
1992	134.24
1993	138.62
1994	142.94
1995	147.68
1996	152.85
1997	158.87
1998	164.91
1999	168.87
2000	171.7
2001	175.62
2002	178.41
2003	180.59
2004	181.41
2005	180.96
2006	182.84
2007	189.6
2008	198.8
2009	205.86
2010	208.98
2011	205.66
2012	204.24
2013	202.06
2014	201.18
2015	201.75
2016	204.4