Year	Number of
1990	79.45
1991	81.56
1992	83.93
1993	86.53
1994	89.26
1995	92.15
1996	98.45
1997	105.37
1998	112.97
1999	121.27
2000	130.51
2001	137.46
2002	144.84
2003	152.54
2004	160.6
2005	169.13
2006	174.58
2007	179.91
2008	185.37
2009	190.87
2010	196.56
2011	198.57
2012	200.88
2013	203.22
2014	205.86
2015	208.83
2016	212.68