Year	Number of
1990	68.96
1991	73.06
1992	76.92
1993	81.07
1994	85.21
1995	89.36
1996	92.92
1997	96.9
1998	100.44
1999	102.74
2000	106.72
2001	111.55
2002	116.93
2003	121.83
2004	126.69
2005	130.59
2006	135.25
2007	140.89
2008	148.38
2009	157.54
2010	165.62
2011	173.6
2012	180.43
2013	186.98
2014	193.77
2015	199.75
2016	204.29