Year	Number of
1990	99.91
1991	103.9
1992	108.41
1993	114.35
1994	121.08
1995	127.66
1996	132.62
1997	137.36
1998	143.14
1999	148.38
2000	154.37
2001	160.46
2002	166.75
2003	173.26
2004	180.08
2005	186.31
2006	191.24
2007	196.42
2008	203.16
2009	210.68
2010	219.56
2011	225.76
2012	232.85
2013	240.26
2014	248.49
2015	257.71
2016	266.8