Year	Number of
1990	69.97
1991	73.2
1992	76.67
1993	80.49
1994	84.64
1995	89.12
1996	92.91
1997	96.96
1998	101.26
1999	105.75
2000	110.6
2001	114.57
2002	118.92
2003	123.7
2004	128.71
2005	134.16
2006	138.81
2007	143.36
2008	147.95
2009	152.73
2010	158.38
2011	164.14
2012	170.63
2013	177.42
2014	184.71
2015	192.5
2016	201.27