Year	Number of
1990	93.77
1991	98.76
1992	104.07
1993	109.92
1994	115.77
1995	121.87
1996	125.17
1997	129.05
1998	131.75
1999	134.69
2000	138.14
2001	140.57
2002	143.35
2003	146.68
2004	150.47
2005	155.09
2006	158.94
2007	163.02
2008	168.06
2009	173.64
2010	180.06
2011	186.09
2012	192.91
2013	200.03
2014	207.69
2015	215.89
2016	224.95