Year	Number of
1990	71.47
1991	73.68
1992	76.46
1993	79.67
1994	83.21
1995	86.99
1996	93.49
1997	100.55
1998	108.14
1999	116.23
2000	124.92
2001	127.64
2002	130.56
2003	134.16
2004	138.32
2005	143.23
2006	147.69
2007	152.61
2008	158.15
2009	163.86
2010	169.66
2011	175.62
2012	181.65
2013	187.47
2014	193.66
2015	200.41
2016	207.92